Proportions Hypothesis Testing

Identify the correct null hypothesis: Is the proportion of babies born male different from 50%? In a sample of 200 babies, 96 were male. Test the claim using a level of significance of 1%.

• H₀: p = 0.50

• H₀: µ = 100

• H₀: p = 0.48

• H₀: µ = 96

When performing a test about the population proportion, what distribution would you need to use? 

• z

• t

• chi-square

What is the critical value (in a test about proportions) for a left-tailed test with α = 0.05 and n ≥ 30.

• z₀ = -1.645

• z₀ = -2.33

• z₀ = -1.96

• z₀ = 2.58

A mayor is concerned about the percentage of city residents who express disapproval of his job performance. His political committee pays for a newspaper ad, hoping to keep his disapproval rating below 21%. They will use a follow up poll to access effectiveness. What are the correct null and alternative hypotheses?

• Ho: μ > 21

  Ha: μ < 21

• Ho: p > .20

  Ha: p < .20

• Ho: p < .21

  Ha: p > .21

• Ho: p > .21

  Ha: p < .21

Elsie bought a new bowling ball. She suspects that she'll roll a strike in a larger percentage of rolls with her new ball than her old ball. She takes a sample of 50 rolls with each ball to test if she rolls a strike significantly more often with the new ball.

Which of the following is an appropriate set of hypotheses for Elsie's significance test?

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If the difference of two proportions (p₁-p₂) shows a confidence interval of (-0.13, 0.32), what would have been our decision from the 2-prop z-test?

• Fail to reject Ha since 0 is in the interval

• Fail to reject Ho since 0 is in the interval

• Reject Ho since 0 is in the interval

• Reject Ha since 0 is in the interval

Kiley has a dime and a nickel, and she wonders if they have the same likelihood of showing heads when they are flipped. She flips each coin 100 times to test if there is a significant difference in the proportion of flips that they each land showing heads.

Which of the following is an appropriate set of hypotheses for Kiley's significance test?

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A study was done to see if the probability of allergies increased if owning a cat. They randomly sampled 58 people who owned a cat and 34 people who did not own a cat to see if they had allergies or not.

Which hypotheses is correct

In testing hypotheses, which of the following would be strong evidence against the null hypothesis?

• using a small level of significance

• using a large level of significance

• obtaining data with a small p-value

• obtaining data with a low test statistic

Suppose the P-value for a hypothesis test is 0.0304. Using a = 0.05, what is the appropriate conclusion?

• Reject the null hypothesis

• Reject the alternative hypothesis

• Fail to reject the null hypothesis

• Fail to reject the alternative hypothesis