p.6
Survey Methodology and Sampling Techniques
How is each element in the sampling frame identified?
By giving each element a unique identity number.
p.16
Descriptive Statistics: Measures of Variation
Can two data sets with the same mean have different spreads?
Yes, they can have completely different spreads.
p.9
Survey Methodology and Sampling Techniques
Why is it impractical to prepare a sampling frame for the example provided?
Because the population size is very large, all teenagers in Hong Kong.
p.14
Descriptive Statistics: Measures of Central Tendency
In the provided example with a sample size of 15, what is the mode?
There is no mode as all data have the same frequency.
p.9
Survey Methodology and Sampling Techniques
What is the population size in the example regarding the cola brand survey?
All teenagers in Hong Kong.
p.4
Survey Methodology and Sampling Techniques
What does a census involve in the context of employee satisfaction?
Collecting data from every employee in the company.
p.9
Survey Methodology and Sampling Techniques
What is a convenience sample?
A sample selected based on ease of access, such as street interviews.
p.6
Survey Methodology and Sampling Techniques
What is a disadvantage of Simple Random Sampling?
It can be time-consuming for large-scale surveys.
p.17
Descriptive Statistics: Measures of Central Tendency
What is Q1 in the provided example?
Q1 = 420 items (25th percentile).
p.14
Descriptive Statistics: Measures of Central Tendency
What is the mode in a data set?
The value that occurs most frequently.
p.1
Statistical Concepts and Terminology
What is one of the key topics covered in the Elementary Statistics course?
Probability Distributions.
p.32
Expected Value and Variance of Random Variables
What does the positive square root of the variance represent?
The standard deviation of X.
p.4
Survey Methodology and Sampling Techniques
What is crucial for the reliability of conclusions drawn from a survey?
How representative the sample is of the population.
p.17
Descriptive Statistics: Measures of Central Tendency
What is Q3 in the provided example?
Q3 = 890 items (75th percentile).
p.20
Statistical Concepts and Terminology
What characterizes a symmetric distribution?
In a symmetric distribution, the parts above and below its center are mirror images in the density function.
p.20
Statistical Concepts and Terminology
What indicates a right-skewed distribution?
A right-skewed distribution has a longer right side.
p.17
Descriptive Statistics: Measures of Variation
Is the interquartile range affected by extreme values?
No, it is not affected by extreme values.
p.20
Statistical Concepts and Terminology
What indicates a left-skewed distribution?
A left-skewed distribution has a longer left side.
p.24
Calculator Usage for Statistical Analysis
How do you clear previous data on the Casio fx-50FH calculator?
Press SHIFT, then CLR, select Stat, and press EXE.
p.13
Descriptive Statistics: Measures of Central Tendency
What is the sample mean?
The average result calculated from a subset of the population, which can vary depending on the selected data.
p.18
Descriptive Statistics: Measures of Variation
How is standard deviation related to variance?
Standard deviation is the square root of the variance.
p.27
Random Variables: Discrete vs Continuous
What are the characteristics of a numerical random variable?
Its value is uncertain and unpredictable, and it can be presented as a numerical value.
p.28
Probability and Probability Distributions
Why is summarizing a discrete variable as a probability distribution function useful?
It helps understand the possible range of outcomes and evaluate which outcomes have higher chances of occurring.
p.12
Descriptive Statistics: Measures of Central Tendency
What are the three major types of descriptive measures in statistics?
Central tendency, variation, and shape.
p.17
Descriptive Statistics: Measures of Variation
What is the interquartile range (IQR)?
The difference between the third quartile (Q3) and the first quartile (Q1) in a set of data.
p.1
Course Overview and Objectives
What is the significance of the course in relation to further studies?
It cultivates interest in quantitative techniques necessary for further studies.
p.4
Descriptive Statistics: Measures of Central Tendency
What statistical analyses might be performed after data collection?
Calculation of mean and standard deviation of the scores.
p.8
Survey Methodology and Sampling Techniques
How are individual samples selected in stratified sampling?
Randomly from each of the strata.
p.34
Expected Value and Variance of Random Variables
What is the formula for variance of Y?
Var(Y) = Σ [f(xi)² * p(xi)] - E(Y)².
p.3
Survey Methodology and Sampling Techniques
What are some methods to collect a representative sample?
Simple random sampling, systematic sampling, and stratified sampling.
p.25
Probability and Probability Distributions
What is empirical probability?
Probability based on observed frequencies from experiments.
p.26
Probability and Probability Distributions
What is a key analysis method for a normal variable?
Analyzing a function of a normal variable.
p.2
Course Overview and Objectives
What should you check frequently for updated course information?
SOUL course link and class link.
p.31
Expected Value and Variance of Random Variables
Why might the average number of books borrowed (4.35) not reflect individual borrowing behavior?
Because not every reader borrows the same amount, and it's not possible to borrow a fractional number of books.
p.15
Descriptive Statistics: Measures of Variation
What should you do if the index i is not an integer?
Round up i to the nearest integer.
p.6
Survey Methodology and Sampling Techniques
What is Simple Random Sampling?
A method that selects objects such that every object of the population has an equal chance of being selected.
p.28
Probability and Probability Distributions
What does the notation P(X = x) represent?
The probability that the random variable X takes on the value x.
p.1
Course Overview and Objectives
What type of assessment is included in the course?
Individual assignments and a final examination, each worth 50 marks.
p.27
Random Variables: Discrete vs Continuous
What is the numerical random variable for a tour guide managing tourists?
The number of tourists that may go to Ocean Park.
p.8
Survey Methodology and Sampling Techniques
What is stratified sampling?
A method that divides the whole population into subgroups (strata) based on a common characteristic.
p.7
Survey Methodology and Sampling Techniques
What is systematic sampling?
A method that selects the first object randomly and the rest by a fixed interval k.
p.18
Descriptive Statistics: Measures of Variation
What do variance and standard deviation evaluate?
How the values fluctuate about the mean.
p.25
Probability and Probability Distributions
Define an event in probability.
Each possible type of occurrence in a sample space.
p.29
Probability and Probability Distributions
How can we determine the probability distribution function for an unfair die?
By conducting experiments and calculating empirical probabilities based on observed relative frequencies.
p.29
Probability and Probability Distributions
What is the probability distribution function based on the observed frequencies from the die toss?
1: 0.18, 2: 0.12, 3: 0.32, 4: 0.16, 5: 0.12, 6: 0.10.
p.20
Descriptive Statistics: Measures of Variation
What is an example of a right-skewed distribution?
Monthly income of fresh graduates.
p.10
Statistical Concepts and Terminology
What are the two types of variables in statistics?
Numerical variable and categorical variable.
p.5
Survey Methodology and Sampling Techniques
What is a sampling frame?
A data file that contains information of the population objects.
p.2
Calculator Usage for Statistical Analysis
What type of calculator is required for the course?
An HKEA approved calculator with SD (statistics) function.
p.10
Statistical Concepts and Terminology
What is a continuous numerical variable?
Data that covers a range of values.
p.31
Expected Value and Variance of Random Variables
What is the probability distribution function p(x) for the number of books borrowed?
P(X=x) = {0.02, 0.07, 0.15, 0.28, 0.33, 0.10, 0.03, 0.02} for x = {1, 2, 3, 4, 5, 6, 7, 8}.
p.14
Descriptive Statistics: Measures of Central Tendency
How is the mode different from other measures of central tendency?
The mode is not affected by extreme values.
p.27
Random Variables: Discrete vs Continuous
In the context of a librarian, what is a numerical random variable?
The number of books the next reader may borrow.
p.4
Survey Methodology and Sampling Techniques
Why might a survey be conducted instead of a census?
Due to limitations like time and budget.
p.19
Descriptive Statistics: Measures of Variation
What is the significance of standard deviation in relation to the mean?
It indicates the average difference of the data from the mean.
p.7
Survey Methodology and Sampling Techniques
In the example provided, what is the sample size and total population?
Sample size is 500 and total population is 3000 employees.
p.30
Probability and Probability Distributions
What are the two methods to prepare the probability distribution function?
Method 1: Use past records of tourists visiting Ocean Park. Method 2: Use a theoretical Binomial distribution based on a 60% visit rate.
p.12
Descriptive Statistics: Measures of Central Tendency
What is a key characteristic of the mean?
It is affected by extreme values.
p.20
Descriptive Statistics: Measures of Variation
How can skewness be identified using quartiles?
By comparing Q1, Q2, and Q3: symmetric if Q2 - Q1 = Q3 - Q2, left-skewed if Q2 - Q1 > Q3 - Q2, and right-skewed if Q2 - Q1 < Q3 - Q2.
p.21
Descriptive Statistics: Measures of Variation
What does it indicate if Q2 - Q1 > Q3 - Q2?
The distribution is left skewed.
p.26
Probability and Probability Distributions
What can be calculated for a function of a variable?
Expected value, variance, and standard deviation.
p.24
Calculator Usage for Statistical Analysis
How do you calculate the mean on the Casio fx-50FH calculator?
Press SHIFT, then 2, then 1, and then EXE.
p.10
Statistical Concepts and Terminology
What is a discrete numerical variable?
Data that only takes place at particular values, usually integers.
p.35
Expected Value and Variance of Random Variables
What is the expected value of Y if E(X) = 2.15?
E(Y) = -3500 + 4340(2.15) = $5831.
p.22
Linear Functions of Random Variables
What is the relationship between the mean of Y and the mean of X in a linear function?
Mean(Y) = a + b * Mean(X)
p.11
Statistical Concepts and Terminology
What type of variable is the number of previous full-time employment?
Discrete numerical variable.
p.28
Probability and Probability Distributions
What is a probability distribution function for a discrete random variable?
A mutually exclusive listing of all possible numerical outcomes with associated probabilities.
p.28
Probability and Probability Distributions
What are the properties of a probability distribution function?
1. 0 ≤ p(x) ≤ 1 for all x; 2. The sum of p(x) over all possible values of x equals 1.
p.20
Statistical Concepts and Terminology
What is skewness in data distribution?
Skewness refers to the asymmetry of the distribution of data values.
p.4
Descriptive Statistics: Measures of Central Tendency
What does a mean satisfaction score of 2.4 indicate?
A very low level of satisfaction.
p.3
Survey Methodology and Sampling Techniques
What is the basic workflow of conducting a survey?
It involves planning, collecting data, and summarizing findings.
p.30
Probability and Probability Distributions
What is the probability that 4 to 8 tourists will visit Ocean Park?
The probability is 0.899.
p.18
Descriptive Statistics: Measures of Variation
What does a small variance indicate?
The data points are located closely together.
p.13
Descriptive Statistics: Measures of Central Tendency
How is the population mean calculated in the example provided?
By averaging the examination results of all year 1 students, resulting in a mean of 78.65 marks.
p.15
Descriptive Statistics: Measures of Variation
What is the p-th percentile?
The maximum value that (about) p% of the observations are smaller than.
p.15
Descriptive Statistics: Measures of Variation
How is the index i calculated for finding the p-th percentile?
i = n * (p/100), where n is the number of data points.
p.15
Descriptive Statistics: Measures of Variation
What does the 50th percentile represent?
The second quartile (Q2), which is the median.
p.11
Statistical Concepts and Terminology
What type of variable is total working hours on 1/9/2019?
Continuous numerical variable.
p.11
Statistical Concepts and Terminology
How is collected data typically denoted?
With a small letter (e.g., x).
p.9
Survey Methodology and Sampling Techniques
When is a convenience sampling method practical?
When no sampling frame is available.
p.27
Random Variables: Discrete vs Continuous
What numerical random variable is analyzed by a researcher in telecommunications?
The duration of long-distance calls.
p.6
Survey Methodology and Sampling Techniques
How can using computer software improve the sampling process?
It can generate random numbers much faster while maintaining the same underlying logic.
p.7
Survey Methodology and Sampling Techniques
How is the fixed interval k calculated in systematic sampling?
k = total population size / sample size.
p.17
Descriptive Statistics: Measures of Variation
What does the interquartile range measure?
The spread of the middle 50% of the data.
p.33
Random Variables: Discrete vs Continuous
What does X represent in the example provided?
The number of photocopiers sold in a week.
p.12
Descriptive Statistics: Measures of Central Tendency
What happens when you multiply the mean by the number of data points?
It equals the total value.
p.24
Calculator Usage for Statistical Analysis
What is the command to input data into the Casio fx-50FH calculator?
Input each data point followed by pressing DT.
p.7
Survey Methodology and Sampling Techniques
What is a disadvantage of systematic sampling?
The sample may be biased when studying periodic data.
p.31
Expected Value and Variance of Random Variables
What is the expectation (or expected value) of a discrete random variable X?
It is the weighted average over all possible outcomes, with weights being the probabilities associated with each outcome.
p.2
Calculator Usage for Statistical Analysis
Are calculators with graphical displays allowed in the examination?
No, they will not be allowed.
p.13
Statistical Concepts and Terminology
What will be explored in Chapter 4 regarding sample means?
Using a randomly selected sample mean to estimate the population mean with high accuracy.
p.10
Statistical Concepts and Terminology
In the provided survey example, what type of variable is 'Number of previous full-time employment'?
Numerical variable (Discrete).
p.1
Course Overview and Objectives
What is the primary focus of the Elementary Statistics course?
Teaching quantitative skills applicable to daily life problems.
p.6
Survey Methodology and Sampling Techniques
What is the first step in the sampling process for selecting employees?
Assign unique identity numbers to each employee from 0001 to 3000.
p.6
Survey Methodology and Sampling Techniques
What happens if the same number is selected more than once?
It must also be discarded.
p.8
Survey Methodology and Sampling Techniques
What are strata in stratified sampling?
Subgroups that are mutually exclusive and exhaustive.
p.20
Statistical Concepts and Terminology
How can distributions be classified based on skewness?
Distributions can be classified as symmetric, left-skewed, or right-skewed.
p.17
Descriptive Statistics: Measures of Variation
What is the interquartile range (IQR) for the given data?
IQR = 890 – 420 = 470 items.
p.33
Random Variables: Discrete vs Continuous
What is a function of a random variable?
A function Y = f(X) where Y is studied based on the random variable X.
p.26
Probability and Probability Distributions
What is the focus of Chapter 2 in Elementary Statistics?
Methods to describe characteristics of a numerical random variable.
p.5
Survey Methodology and Sampling Techniques
What is a population in statistics?
The totality of elements (items, objects) under consideration.
p.24
Calculator Usage for Statistical Analysis
What is the command to calculate the population standard deviation?
Press SHIFT, then 2, then 2, and then EXE.
p.5
Survey Methodology and Sampling Techniques
Why should probability samples be used?
To minimize the possible chance of getting biased results.
p.10
Statistical Concepts and Terminology
What does a numerical variable consist of?
Data that consists of numbers representing counts or measurements.
p.13
Descriptive Statistics: Measures of Central Tendency
Why is the sample mean not unique?
Its value depends on which data are selected in the sample.
p.15
Descriptive Statistics: Measures of Variation
What is the first step in finding the p-th percentile?
Arrange data in an ordered array.
p.10
Statistical Concepts and Terminology
In the provided survey example, what type of variable is 'Total working hours on 1/9/2019'?
Numerical variable (Continuous).
p.11
Statistical Concepts and Terminology
How is a variable typically denoted?
With a capital letter (e.g., X).
p.9
Survey Methodology and Sampling Techniques
What is the example given for selecting a sample of teenagers?
Inviting 500 teenagers to join a survey about a cola brand.
p.16
Descriptive Statistics: Measures of Variation
What does variation measure in a data set?
The amount of dispersion or spread in the data.
p.4
Descriptive Statistics: Measures of Central Tendency
What does a mean satisfaction score of 9.5 indicate?
A very high level of satisfaction.
p.34
Expected Value and Variance of Random Variables
How is the expected weekly profit calculated?
By substituting values of X into the profit function and using the probability distribution.
p.12
Descriptive Statistics: Measures of Central Tendency
What does the mean represent in a data set?
It shares the total by the number of data equally.
p.18
Descriptive Statistics: Measures of Variation
What is the formula for sample variance?
s² = (1/(n-1)) * Σ(x - x̄)²
p.3
Survey Methodology and Sampling Techniques
What is the difference between a census and a sample survey?
A census collects data from every member of a population, while a sample survey collects data from a subset.
p.26
Probability and Probability Distributions
Why is understanding the probability distribution of a variable important?
It provides insight to predict outcomes under uncertain situations.
p.13
Descriptive Statistics: Measures of Central Tendency
What is the population mean?
The average result of all individuals in a population, reflecting its characteristics, calculated when a census is conducted.
p.5
Survey Methodology and Sampling Techniques
What is a census?
Investigation based on the data of the whole population.
p.3
Survey Methodology and Sampling Techniques
What is the objective of the survey conducted by the manager?
To understand the employees' satisfaction level towards the company.
p.3
Statistical Concepts and Terminology
What scale is used to measure employee satisfaction?
A 10-point scale ranging from 0 (very unsatisfied) to 10 (very satisfied).
p.3
Survey Methodology and Sampling Techniques
What is the most ideal method for conducting the survey?
Conducting a census of all 3000 employees.
p.3
Descriptive Statistics: Measures of Central Tendency
What summary statistics might be used in the survey results?
Mean, standard deviation, 25th percentile, and 75th percentile.
p.31
Expected Value and Variance of Random Variables
What does the variance measure in the context of a discrete random variable?
It measures the dispersion of the variable.
p.22
Linear Functions of Random Variables
What is the formula for the range of Y in terms of the range of X?
Range(Y) = |b| * Range(X)
p.1
Course Overview and Objectives
What should students be able to do upon completion of the Elementary Statistics course?
Apply fundamental statistical skills in practice and analyze and present data using basic statistical methods.
p.14
Descriptive Statistics: Measures of Central Tendency
Can the mode be used in categorical data sets?
Yes, the mode can also be used in categorical data sets.
p.27
Random Variables: Discrete vs Continuous
What is an example of a numerical random variable when tossing a die?
The side that may face up.
p.32
Expected Value and Variance of Random Variables
How is the variance of X defined?
As the weighted average of the squared discrepancies between each possible outcome and its mean.
p.16
Descriptive Statistics: Measures of Variation
What do measures of central tendency and variation together provide?
A good picture of a data set.
p.30
Statistical Concepts and Terminology
What is the variable Y in the example?
The number of tourists, out of a group of 10, who will go to Ocean Park.
p.7
Survey Methodology and Sampling Techniques
How do you select the first subject in systematic sampling?
Randomly from the first k employees using a random number table.
p.26
Probability and Probability Distributions
What are the key components used to summarize a numerical discrete variable?
Probability distribution function, expected value, variance, and standard deviation.
p.33
Probability and Probability Distributions
What is the probability distribution function for the number of 'PhotoC' sold?
x: 0, 1, 2, 3, 4, 5; p(x): 0.05, 0.22, 0.38, 0.24, 0.10, 0.01.
p.5
Survey Methodology and Sampling Techniques
What are examples of a sampling frame?
Telephone directory, student registration list, employment record.
p.35
Expected Value and Variance of Random Variables
What is the variance of Y if Var(X) = 1.1275?
Var(Y) = 4340²Var(X) = 21237139 ($²).
p.22
Linear Functions of Random Variables
How can the percentile of Y be expressed in terms of the percentile of X?
Percentile pth (Y) = a + b * Percentile pth (X)
p.27
Random Variables: Discrete vs Continuous
What defines discrete data?
Data that only takes place at particular values.
p.19
Descriptive Statistics: Measures of Variation
Why is the sample variance calculated using n - 1?
To make it the best estimator of the population variance.
p.12
Descriptive Statistics: Measures of Central Tendency
How is the sample mean calculated from the sales data example?
Sample mean = 648.73 items.
p.25
Probability and Probability Distributions
What is a sample space?
The collection of all possible events in an experiment.
p.18
Calculator Usage for Statistical Analysis
How can sample standard deviation be calculated besides using the formula?
By inputting the dataset into a calculator.
p.5
Survey Methodology and Sampling Techniques
What are the two main types of survey sampling methods?
Probability samples and non-probability samples.
p.24
Calculator Usage for Statistical Analysis
How can you change a data point on the Casio fx-50FH calculator?
Use ▲/▼ until you see the data point, then input the new value and press EXE.
p.24
Calculator Usage for Statistical Analysis
What is the process to delete a data point on the Casio fx-50FH calculator?
Use ▲/▼ until you see the data point, then press SHIFT and DT.
p.10
Statistical Concepts and Terminology
What is a nominal categorical variable?
A variable with no natural order between categories.
p.11
Statistical Concepts and Terminology
What are the categories for highest education level in order?
'Undergraduate', 'HKALE graduate', 'HKCEE graduate'.
p.16
Descriptive Statistics: Measures of Variation
What is the range in a data set?
The difference between the largest and smallest observations.
p.28
Probability and Probability Distributions
What are some methods to prepare a probability distribution function?
Theoretical approach, experiment, observation, survey, etc.
p.27
Random Variables: Discrete vs Continuous
What defines continuous data?
Data that covers a range of values.
p.24
Calculator Usage for Statistical Analysis
What is the first step to use the Casio fx-50FH calculator for descriptive statistics?
Change to 'SD' mode by pressing MODE twice and then SD.
p.8
Survey Methodology and Sampling Techniques
What is one advantage of stratified sampling?
It can avoid unbalanced selection.
p.25
Probability and Probability Distributions
How many combinations are there when selecting 3 students from 10?
10 C 3 = 120 possible combinations.
p.26
Probability and Probability Distributions
What is the purpose of reading the probability density function?
To analyze a numerical continuous variable.
p.26
Probability and Probability Distributions
What can be calculated for a normal variable?
The probability function.
p.26
Probability and Probability Distributions
What does locating the normal score of a normal variable involve?
Identifying the position of a value within a normal distribution.
p.25
Probability and Probability Distributions
What is the probability of getting a 1 on the first toss and a 6 on the second toss of an unfair die?
P(first 1 and the second 6) = 0.0242.
p.13
Statistical Concepts and Terminology
What will be discussed in Chapter 3 regarding sample means?
The relationship between random sample means and the population mean.
p.10
Statistical Concepts and Terminology
In the provided survey example, what type of variable is 'Gender'?
Categorical variable (Nominal).
p.22
Linear Functions of Random Variables
How is the variance of Y calculated in terms of the variance of X?
Variance(Y) = b² * Variance(X)
p.16
Descriptive Statistics: Measures of Variation
How is the range calculated?
Range = Maximum data – Minimum data.
p.23
Descriptive Statistics: Measures of Central Tendency
What is the formula for calculating the monthly salary of a salesperson?
Y = 20000 + 30X, where X is the number of items sold.
p.19
Descriptive Statistics: Measures of Variation
Why is standard deviation more commonly used than variance?
Because it is in the original units of the data.
p.7
Survey Methodology and Sampling Techniques
What is the first step in the systematic sampling process?
Assign unique identity numbers to each employee.
p.29
Probability and Probability Distributions
What is the probability distribution function for a fair die?
Each outcome (1 to 6) has a probability of 1/6.
p.20
Descriptive Statistics: Measures of Variation
What is an example of a symmetric distribution?
The height of a 10-year-old boy.
p.3
Descriptive Statistics: Measures of Central Tendency
How can a numerical dataset be presented?
Using mean, mode, percentile, range, inter-quartile range, variance, standard deviation, and skewness.
p.35
Expected Value and Variance of Random Variables
What is the formula for the expected value of Y when Y is a linear function of X?
E(Y) = a + bE(X), where Y = a + bX.
p.10
Statistical Concepts and Terminology
What does a categorical variable consist of?
Data that consists of names representing categories.
p.10
Statistical Concepts and Terminology
What is an ordinal categorical variable?
A variable where there exists a natural order between categories.
p.8
Survey Methodology and Sampling Techniques
What is the major idea behind stratified sampling?
To ensure the same proportion of representatives in each of the strata.
p.25
Probability and Probability Distributions
What is probability?
The likelihood or chance that a particular event will occur.
p.19
Descriptive Statistics: Measures of Variation
What does the variance represent in terms of units?
Squared units of the original data, e.g., squared dollars.
p.18
Descriptive Statistics: Measures of Variation
What does (x - μ)² measure?
The square difference of the data point to the mean.
p.3
Statistical Concepts and Terminology
What is the difference between numerical and categorical variables?
Numerical variables represent measurable quantities, while categorical variables represent categories or groups.
p.29
Probability and Probability Distributions
What were the frequencies observed when tossing a die 100 times?
1: 18, 2: 12, 3: 32, 4: 16, 5: 12, 6: 10.
p.5
Survey Methodology and Sampling Techniques
What is a sample?
A portion of the population selected for analysis.
p.31
Expected Value and Variance of Random Variables
How is the expectation of a discrete random variable X denoted?
It is denoted by μX or E(X).
p.31
Expected Value and Variance of Random Variables
What does the mean of X represent in the long run?
It represents the average value of X.
p.5
Survey Methodology and Sampling Techniques
Why is an updated sampling frame important?
It ensures every element has a chance to be selected for probability samples.
p.13
Survey Methodology and Sampling Techniques
What is the goal of selecting a 'good representative' sample?
To ensure the sample mean is reasonably close to the unknown population mean.
p.35
Expected Value and Variance of Random Variables
What is the average weekly profit gained by selling PhotoC?
The average weekly profit is $5831.
p.15
Descriptive Statistics: Measures of Variation
What if the index i is an integer?
The p-th percentile is the average of the values at the i-th and (i+1)-th positions.
p.26
Probability and Probability Distributions
What is used to summarize a Binomial variable?
Probability distribution function, expected value, variance, and standard deviation.
p.29
Probability and Probability Distributions
How can we generate the probability distribution function for the number of books borrowed from a library?
By using the relative frequency from the library's borrowing records.
p.29
Probability and Probability Distributions
What is the probability distribution function for the number of books borrowed (1 to 8)?
1: 0.02, 2: 0.07, 3: 0.15, 4: 0.28, 5: 0.33, 6: 0.10, 7: 0.03, 8: 0.02.
p.24
Calculator Usage for Statistical Analysis
How do you input frequency for multiple observations on the Casio fx-50FH calculator?
Input the repeated value followed by SHIFT, then 4, and DT.
p.31
Expected Value and Variance of Random Variables
What is the significance of the probabilities in the expectation formula?
They act as weights for the outcomes in the calculation of the expected value.
p.35
Expected Value and Variance of Random Variables
What is the standard deviation of Y if σ(X) = 1.0618?
σ(Y) = |4340|σ(X) = $4608.38.
