Question

An article on the effect of aerosol species on atmospheric visibility reported that for 20 samples taken in the winter, the mass ratio of fine to coarse particles averaged 0.51 with a standard deviation of 0.09, and for 14 samples taken in the summer the mass ratio averaged 0.65 with a standard deviation of 0.11. Let μ 1 represent the mean mass ratio during the winter and let μ 2 represent the mean mass ratio during the summer. We wish to test H 0 : μ 2 − μ 1 = 0.1 versus H a : μ 2 − μ 1 > 0.1 .

a) The absolute value of the test statistic for this test is closest to:

b) The test statistic has has the following distribution: [ Select ] ["Chi-squared distribution", "Binomial distribution", "Z-distribution", "T-distribution"]

c)

In a test of hypothesis with

H 0 : μ 1 − μ 2 = 0 ; H a : μ 1 − μ 2 ≠ 0 ,

which test statistic provides the most evidence against the null hypothesis?

Answer 1

a) Test Statistic:

b) T-distribution is best to the given data

c) The test statistic provides the most evidence against the null hypothesis is