Chapter 4 Test Review

Increasing the size of an SRS has these beneficial effects:

• the bias of the sample is reduced relative to smaller SRSs
• the variability is smaller than it is for smaller SRSs
• nonsampling errors become less important

When we take a census, we attempt to collect data from

• Stratified randome sample
• every individual selected in a simple random sample
• every individual in the population
• a convenience sample

A table of random numbers is used to select 30 students from a statistics class to rate a statistics video. The ratings that these students give are used to estimate the ratings that would be given if the entire class were asked to rate the video. The true average of the ratings of all students in the class is

• a population parameter
• a convenience sample
• a census
• a statistics that is an unbiased estimate of the class rating

An instructor has five sections of a course: A, B, C, D, and E. She wants to randomly select three sections for a special teaching evaluation. She labels the classes as follows: A = 1, B= 2, C = 3, D =4 and E =5. She starts at the beginning of this list of random digits:  15689 14227 06565 14374 Which classes did she select?   

• A, E and A
• A and D
• A, B and C
• A, E  and D

Which of the following is correct?

• parameters describe population characteristics                     
• parameters describe sample characteristics
• the population is a subset of the sample                     
• statistics must be based on a simple random sample

If a sampling method is biased then

• we need to improve the sampling method to remove the bias
• we need to increase the sample size to remove the bias
• we should sample from a larger population
• the sample statistic will be close to the population paramter

If we take a simple random sample of size n=500 from a population of size 5,000,000, the variability of our estimate will be

• less than the bias
• much less than the variability for a sample of size n=500 from a population of size 50,000,000
• approximately the same as the variability for a sample of size n=500 from a population of size 50,000,000
• much greater than the variability for a sample of size n=500 from a population of size 50,000,000

To reduce the variability of estimates from a simple random sample, you should

• use a smaller sample
• increase the bias
• use a larger sample
• use a count not a percent

A survey was sent to a simple random sample of college sophomores. The sample size was 300. When asked whether or not they liked Willie Nelson's music, 35 of these students did not give any answer. This is an example of       

• stratified sample
• census
• bias
• nonresponse

To take a sample of students in this class we make a list ordered by social security number and select every 20th student in this list to be in our sample. This is an example of   

• systematic sampling
• simple random sampling
• stratified random sampling
• cluster sampling