Quizizz 6.1 (Ch. 5, Section 1-3)

Some doctors who did not give any charity care may say that they did. If so, the study suffers from

• a large margin of error to take account of possible failure to be truthful.
• sampling errors that require a better random sampling design.
• bias: the sample result will systematically underestimate thetrue percent of doctors who give charity care.
• bias: the sample result will systematically overestimate thetrue percent of doctors who give charity care.

A census is

• a simple random sample from the population.
• a count of a nation's people.
• a sample that does not use chance selection.
• a sample that attempts to include the entire population.

A simple random sample is

• any sample selected by using chance.
• any sample that gives every individual the same chance to be selected.
• a sample that gives every possible sample of the same size thesame chance to be selected.
• a sample that selects equal numbers of individuals from each stratum.

Your statistics class has 30 students. You want to call an SRS of 5 students from your class to ask where they use a computer for the online exercises. You label the students 01, 02, . . . , 30. You 
14459 26056 31424 80371 65103 62253 22490 61181
Your SRS contains the students labeled

• 14, 45, 92, 60, 56
• 14, 31, 03, 10, 22
• 14, 03, 10, 22, 22
• 14, 03, 10, 22, 06

For a simple random sample of size 10,881, the “quick method”produces a margin of error for 95% confidence of about

• 9.6%
• 3%
• 0.96%
• 0.0096%

Increasing the size of an SRS has these beneficial effects:

• the bias of the sample is reduced relative to smaller SRSs.
• the margin of error is smaller than it is for smaller SRSs.
• nonsampling errors become less important
• (a) and (b) but not (c).

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

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

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

You want to ask a sample of professors at your school how they feel about the tenure system for faculty. You realize that opinions may differ depending on the rank of the professor,especially because assistant professors do not have tenure. So you take separate SRS's of assistant, associate, and full professors and combine them to form your sample. You used a

• simple random sample.
• stratified random sample.
• voluntary response sample.
• convenience sample.

A radio talk show invites listeners to call a telephone number to vote "Yes" or "No" on whether they support a bond issue for anew school. About 1500 people call in. Over 80% say "No." As an estimate of community opinion, this result is

• accurate to within 3% with 95% confidence.
• not precise because the sample size 1500 is too small.
• unethical due to lack of informed consent.
• badly biased due to voluntary response.

Tags

CCSS.HSS.IC.B.3