E-Text Assignment Chap 11

#14 Ð'- A random sample of 15 observations from the first population revealed a sample mean of 350 and a sample standard deviation of 12. A random sample of 17 observations from the second population revealed a sample mean of 342 and a sample standard deviation of 15. At the .10 significance level, is there a difference in the population means?

H0: 1 = 2

H1: 1 2

n1 = 15 n2 = 17 (sample size)

1 = 350 2 = 342 (sample mean)

s1 = 12 s2 = 15 (standard deviation)

= 0.10 (alpha significance level)

Step 1 Ð'- State the Null and Alternative Hypothesis

H0: 1 = 2

H1: 1 2

Step 2 Ð'- Select the Significance Level

= 0.10

Step 3 = n is < than 30, so we use "T" Test Statistics

Step 4 = Find the Critical Value of "T" statistic Ð'- use the Two Tail Test.

Critical Value = 2.749985 // formula =TINV(0.01,15+17-2)

SP2 = 187.2 // formula =((15-1)*12^2+(17-1)*15^2)/(15+17-2)

t = 1.650563 // formula =(350-342)/SQRT(J20*(1/15+1/17))

Step 5 = Solve Ð'- Absolute Value of Test Statistic great than Critical Value then reject H0. Otherwise do not reject H0. (formula used // =IF(1.65>2.75,"reject H0","Do not reject H0")

Based on the decision: Do not reject H0.

#17 Ð'- Ms. Lisa Monnin is the budget director for Nexus Media, Inc. She would like to compare the daily travel expenses for the sales staff and the audit staff. She collected the following sample information?

Sales ($) 131 135 146 165 136 142

Audit ($) 130 102 129 143 149 120 139

At the .10 significance level, can she conclude that the mean daily expenses are greater for the sales staff than the audit staff? What is the p-value?

H0: 1 2

H1: 1 > 2

n1 = 6 n2 = 7 (sample size)

1 = 142.5 2 = 130.2857 (sample mean)

= 0.10 (alpha significance level)

Step 1 Ð'- State the Null and Alternative Hypothesis

(used the right tailed)

H0: 1 2

H1: 1 > 2

Step 2 Ð'- Select the Significance Level

= 0.10

Step 3 = n is < than 30, so we use "T" Test Statistics

Step 4 = Find the Critical Value of "T" statistic Ð'- use the Right Tail Test.

Critical Value = 1.363434 // Used table for formula

t = 1.536796 // Used table for formula

Step 5 = Solve Ð'-Test Statistic greater than Critical Value then reject H0. Otherwise do not reject H0. (formula used // =IF(1.536796>1.36343,"reject