A researcher is interested in testing to determine if the mean price of a casual lunch is different in the city than it is in the suburbs.The null hypothesis is that there is no difference in the population means (i.e.the difference is zero).The alternative hypothesis is that there is a difference (i.e.the difference is not equal to zero).He randomly selects a sample of 9 lunch tickets from the city population resulting in a mean of $14.30 and a standard deviation of $3.40.He randomly selects a sample of 14 lunch tickets from the suburban population resulting in a mean of $11.80 and a standard deviation $2.90.He is using an alpha value of .10 to conduct this test.Assuming that the populations are normally distributed, the critical t value from the table is _______.
A)1.323
B)1.721
C)1.717 This is the value for 22 df (a wrong answer, but a detractor and corrected).
D)1.321
E)2.321

Question

Quizplus · Accepted Answer

Given the sample sizes (n1 = 9 and n2 = 14) and an alpha value of .10 for a two-tailed test, the degrees of freedom (df) can be approximated using the smaller of either n1-1 or n2-1. Here, n1-1 = 8. The critical t value for df = 8 at an alpha level of .10 (two-tailed) is closest to 1.721, which matches option B.

A Researcher Is Interested in Testing to Determine If the Mean