The Next Questions Are Based On The Following Information:
An accountant claims to be able to complete a standard tax return in under an hour.For a random sample of 24 tax returns,the accountant averaged 63.2 minutes with a standard deviation of 7.7 minutes.
-What is the test statistic for this test?
A)Z = 2.04
B)t = 1.79
C)t = 2.04
D)Z = 1.79

Question

Quizplus · Accepted Answer

Since we are dealing with a sample with unknown population standard deviation, we use the t-test. The formula for the t-test is:

t = (x̄ - μ) / (s / sqrt(n))

Where x̄ is the sample mean, μ is the hypothesized population mean, s is the sample standard deviation, and n is the sample size.

In this case, we are testing the hypothesis that the accountant can complete a standard tax return in under an hour, so our null hypothesis is:

H0: μ = 60

Our alternative hypothesis is:

Ha: μ < 60

The test statistic is:

t = (63.2 - 60) / (7.7 / sqrt(24)) = 2.04

Since this is a one-tailed test with 23 degrees of freedom (n – 1), the critical value for a 5% significance level is -1.714. Since 2.04 > -1.714, we reject the null hypothesis and conclude that there is sufficient evidence to support the claim that the accountant takes more than an hour to complete a standard tax return.

The Next Questions Are Based on the Following Information