Quizziz 3/20

If no alpha level is given, what alpha level is assumed?

• 0.01
• 0.05
• 0.10
• 0.25

If no p-hat value is given, what should you assume p-hat equals?

• 0.01

• 0.05

• 0.10

• 0.5

Which of the following hypotheses is a valid example of a 1-tailed test?

• Ho: p = 0.3, Ha: p > 0.4
• Ho: p = 0.3, Ha: p ≠ 0.3
• Ho: p^ = 0.3, Ha: p^ > 0.3
• Ho: p = 0.3, Ha: p > 0.3

A confidence interval estimate is determined from the summer earnings of a SRS of n students. All other things being equal, which of the following will result in a smaller margin of error?

• A greater confidence level
• A larger sample standard deviation
• A larger sample size
• Introducing bias into sampling

Two confidence interval estimates from the same sample are (0.72, 0.83) and (0.75, 0.81). One is at 95%, the other is at 99%. Which is which?

• (0.72, 0.83) is at 99%
• (0.72, 0.83) is at 95% 
• Need to know sample size to determine this
• Need to know standard error to determine this

Tina wants to know if the proportion of people who buy burgers is at all affected by her open mic reading. If p=0.8 before her reading, what is an appropriate set of hypotheses?

• Ho: p = 0.8
  Ha: p > 0.8
• Ho: p = 0.8
  Ha: p < 0.8
• Ho: p ≠ 0.8
  Ha: p = 0.8
• Ho: p= 0.8
  Ha: p ≠ 0.8

Under what conditions would it be meaningful to construct a confidence interval estimate when the data consist of the entire population?

• If the population size is large (n > 30)
• If a higher level of confidence is desired
• If the population is truly random
• Never

What is the z* value for a 88%confidence interval?

• 1.175
• 1.555
• 1.645
• 1.96

In a past General Social Survey, a random sample of men and women answered the question “Are you a member of any sports clubs?” Based on the sample data, 95% confidence intervals for the population proportion who would answer “yes” are .13 to .19 for women and .247 to .33 for men. Based on these results, you can reasonably conclude that 

• At least 25% of American men and American women belong to sports clubs.
• At least 16% of American women belong to sports clubs. 
• There is a difference between the proportions of American men and American women who belong to sports clubs.
• There is no conclusive evidence of a gender difference in the proportion belonging to sports clubs

Null and alternative hypotheses are statements about: 

• population parameters. 
• sample parameters. 
• sample statistics. 
• it depends - sometimes population parameters and sometimes sample statistics.