7. A sample of 40 observations is selected from one population. The sample mean is 102 and the sample standard deviation is 5. A sample of 50 observations is selected from a second population. The sample mean is 99 and the sample standard deviation is 6. Conduct the following test using 95% level of confidence. Z-test for Unpaired data

A. Is it a 1 or 2 tail test
B. Compute the statistical calculation
C. What is your decision regarding H1

Ho = no difference

H1 = second mean < first

Do your Z test (see your statistics text) and accept or reject H1, depending on your level of significance used.

A. To determine whether it is a one-tail or two-tail test, we need to specify the alternative hypothesis. In this case, the question does not provide the alternative hypothesis, so we cannot determine if it is a one-tail or two-tail test.

B. To compute the statistical calculation, we can follow these steps:

1. First, calculate the test statistic, which in this case is the standard score, or the Z-score:

Z = (sample mean 1 - sample mean 2) / √((sample standard deviation 1)^2 / sample size 1 + (sample standard deviation 2)^2 / sample size 2)

Plugging in the given values:
Z = (102 - 99) / √((5^2) / 40 + (6^2) / 50)

2. Calculate the critical value for the desired level of confidence. For a 95% confidence level, the critical value is approximately 1.96 for a two-tail test. However, since we do not know whether it is a one-tail or two-tail test, we cannot determine the critical value.

C. Without the critical value for the desired level of confidence, we cannot make a decision regarding H1. The decision is based on whether the test statistic falls into the critical region or not.