Question

Is the difference between the mean annual salaries of statisticians in Region 1 and Region 2 more than $ 7000?To decide, you select a random sample of statisticians from each region. The results of each survey are shown to the right. At alpha equals 0.10 what should you conclude?

Region 1 Region 2

2 Xbar1 = $68,400 xbar2 = $60,000

Sigma1 = $8750 sigma2 = $9125

N1 = 49 n2 = 43

A. Choose the correct null and alternative hypotheses below.

B. Determine the critical value(s).

C. Determine the rejection region.- Z____

D. Calculate the standardized test statistic fo μ1 - μ2. Z=

E. Reject Ho or failt to reject and why?

Answer 1

A.)

Null Hypothesis, H₀ : μ₁-μ₂ < 7000

Alternative hypotheses, H₁ : μ₁-μ₂ > 7000

B.)it is right tailed test, and the significance level is given as 0.10, the Z critical:

Z_Critical =1.28 (use '=Normsinv(0.90)' in excel)

C.)

Rejection region is Z > 1.28

D.) Test Statistic:

E.)

Here Test Statistic (Z)> Z_critical hence, Reject Ho