Unit 3 Lesson 1: Basics of Hypothesis Testing

Assume the percentage of on-time U.S. airline flights is less than 75%. Also assume that the initial conclusion rejects the null hypothesis. State the final conclusion in simple, nontechnical terms.

A. There is sufficient evidence to support the claim that the percentage of on-time U.S. airline flights is less than 75%

Assume the normal distribution applies to a scenario where you are given H1: p<0.08 in a test using a significance level of a=0.01. Find the critical z value(s)

A. z = -2.33

Given that a test statistic in a left-tailed test is z= - 1.25, use a 0.05 significance level to find the P-value and state the conclusion about the null hypothesis

B. 0.1056; fail to reject the null hypothesis

The standard deviation of duration times (in seconds) of the Old Faithful geyser is less than 40 sec. Identify the null hypothesis and alternative hypothesis in symbolic form.

B. H0: σ= 40 sec; H1: σ<40 sec

Given that a test statistic in a right-tailed test uses a significance level of a=0.02, assume the normal distribution applies and find the critical z value(s)

B. z = 2.05

The majority of college students have credit cards. Identify the null hypothesis and alternative hypothesis in symbolic form.

C. H0: P=0.5; H1: p > 0.5

Assume the normal distribution applies to a scenario where you are given H1: p≠ 0.6 in a test using a significance level of a=0.005. Find the critical z value(s)

C. z = ±2.81

With H1: P>0.75, a test statistic is z=0.55. Use a 0.05 significance level to find the P-value, and state the conclusion about the null hypothesis

D. 0.2912; fail to reject the null hypothesis

The standard deviation of human body temperatures is equal to 0.62F. Identify the null hypothesis and alternative hypothesis in symbolic form

D. H0: σ=0.62F; H1: σ ≠ 0.62F

It is claimed that more than 75% of adults always wear a seat belt in the front seat. A poll of 1012 adults resulted in 870 who say that they always wear a seat belt in the front seat. Find the value of the test statistic z using

D. z = 8.06