One Sample Proportion Z Test

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

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

A 99% confidence interval found that the true proportion of teens who drink coffee every day is in the interval (0.785, 0.831). What was the p^ value used to determine this interval? 

• 0.8

• 0.808

• 0.825

• 0.831

A test was conducted to see if there was evidence that more than 10% of the population is left-handed. Ho: p = 0.10, Ha: p >0.10. A p-value of 1.10 is found. What can we conclude?

• There is not evidence that more than 10% of people are left-handed

• We can conclude that more than 10% of people are left-handed

• There is evidence that more than 10% of people are left-handed

• The person who ran this test made an error

A national health study reported that the proportion of students with elevated blood pressure is 0.15. The principal of a local high school believes that the proportion of students in the school with elevated blood pressure is greater than 0.15. If a large random sample is used, which of the following is the most appropriate test to investigate the principal’s belief?

• A z-test for a proportion

• A z-test for a difference between two proportions

• A chi-square test for homogeneity of proportions

• A t-test for a mean

• A matched-pairs t-test

A researcher is conducting a study of charitable donations by surveying a simple random sample of households in a certain city. The researcher wants to determine whether there is convincing statistical evidence that more than 50 percent of households in the city gave a charitable donation in the past year. Let p represent the proportion of all households in the city that gave a charitable donation in the past year. Which of the following are appropriate hypotheses for the researcher?

• 
• 
• 
• 
• 

A commercial for a breakfast cereal is shown during a certain television program. The manufacturer of the cereal wants to estimate the percent of television viewers who watch the program. The manufacturer wants the estimate to have a margin of error of at most 0.02 at a level of 95 percent confidence. Of the following, which is the smallest sample size that will satisfy the manufacturer’s requirements?

• 40

• 50

• 100

• 1700

• 2500

On the day before an election in a large city, each person in a random sample of 1,000 likely voters is asked which candidate he or she plans to vote for. Of the people in the sample, 55 percent say they will vote for candidate Taylor. A margin of error of 3 percentage points is calculated. Which of the following statements is appropriate?

• The proportion of all likely voters who plan to vote for candidate Taylor must be the same as the proportion of voters in the sample who plan to vote for candidate Taylor (55 percent), because the data were collected from a random sample.

• The sample proportion minus the margin of error is greater than 0.50, which provides evidence that more than half of all likely voters plan to vote for candidate Taylor.

• It is not possible to draw any conclusion about the proportion of all likely voters who plan to vote for candidate Taylor because the 1,000 likely voters in the sample represent only a small fraction of all likely voters in a large city.

• It is not possible to draw any conclusion about the proportion of all likely voters who plan to vote for candidate Taylor because this is not an experiment.

• It is not possible to draw any conclusion about the proportion of all likely voters who plan to vote for candidate Taylor because this is a random sample and not a census.