In order to estimate the difference between the average yearly incomes of marketing managers in the East and West of the United States, the following information was gathered.

East	West
n1 = 39	n2 = 43
x1 = 70 (in $1,000)	x2 = 75 (in $1,000)
s1 = 7 (in $1,000)	s2 = 8 (in $1,000)

(a)

Develop an interval estimate for the difference between the average yearly incomes of the marketing managers in the East and West. Use 98% confidence. (Use East West. Round your answers to three decimal places.)

to

(b)

At = 0.02, use the p-value approach and test to determine if the average yearly income of marketing managers in the East is significantly different from those in the West. (Let d = East West.)

(i)

Formulate the hypotheses.

H₀: _{1 2} > 0

H_a: _{1 2} 0

H₀: _{1 2} 0

H_a: _{1 2} = 0

H₀: _{1 2} = 0

H_a: _{1 2} 0

H₀: _{1 2} 0

H_a: _{1 2} > 0

H₀: _{1 2} 0

H_a: _{1 2} = 0

(ii)

What is the value of the test statistic? (Round your answer to three decimal places.)

(iii)

What is the p-value? (Round your answer to five decimal places.)

p-value =

(iv)

What is your conclusion?

a)Reject H₀. We cannot conclude that there is a significant difference between the average yearly incomes of marketing managers in the East and West.

b)Do not reject H₀. We can conclude that there is a significant difference between the average yearly incomes of marketing managers in the East and West.

c)Do not reject H₀. We cannot conclude that there is a significant difference between the average yearly incomes of marketing managers in the East and West.

d)Reject H₀. We can conclude that there is a significant difference between the average yearly incomes of marketing managers in the East and West.