Will improving customer service result in higher stock prices for the companies providing the better service? "When a company's satisfaction score has improved over the prior year's results and is above the national average (75.7), studies show its shares have a good chance of outperforming the broad stock market in the long run." The following satisfaction scores of three companies for the 4th quarters of two previous years were obtained from an economic indicator. Assume that the scores are based on a poll of70customersfrom each company. Because the polling has been done for several years, the standard deviation can be assumed to equal6 pointsin each case.

CompanyYear 1Year 2Company A7376Company B7577Company C7778(a)

For Company A, is the increase in the satisfaction score from year 1 to year 2 statistically significant? Use= 0.05.

(Let₁= the satisfaction score for year 2and₂= the satisfaction score for year 1.)

State the hypotheses.

H₀:₁₂> 0

H_a:₁₂0

H₀:₁₂0

H_a:₁₂= 0

H₀:₁₂= 0

H_a:₁₂0

H₀:₁₂< 0

H_a:₁₂= 0

H₀:₁₂0

H_a:₁₂> 0

Calculate the test statistic. (Round your answer to two decimal places.)

Calculate thep-value. (Round your answer to four decimal places.)

p-value =

What is your conclusion?

Do not reject H₀. There is sufficient evidence to conclude that the customer service has improved for Company A.

Do not reject H₀. There is insufficient evidence to conclude that the customer service has improved for Company A.

Reject H₀. There is sufficient evidence to conclude that the customer service has improved for Company A.

Reject H₀. There is insufficient evidence to conclude that the customer service has improved for Company A.

(b)

Can you conclude that the year 2 score for Company A is above the national average of75.7? Use= 0.05.

State the hypotheses.

H₀:75.7

H_a:< 75.7

H₀:< 75.7

H_a:= 75.7

H₀:75.7

H_a:= 75.7

H₀:= 75.7

H_a:75.7

H₀:75.7

H_a:> 75.7

Calculate the test statistic. (Round your answer to two decimal places.)

Calculate thep-value. (Round your answer to four decimal places.)

p-value =

What is your conclusion?

Do not reject H₀. There is sufficient evidence to conclude that the score for Company A is above the national average.

Reject H₀. There is sufficient evidence to conclude that the score for Company A is above the national average.

Do not reject H₀. There is insufficient evidence to conclude that the score for Company A is above the national average.

Reject H₀. There is insufficient evidence to conclude that the score for Company A is above the national average.

(c)

For Company B, is the increase from year 1 to year 2 statistically significant? Use= 0.05.

(Let₁= the satisfaction score for year 2and₂= the satisfaction score for year 1.)

State the hypotheses.

H₀:₁₂= 0

H_a:₁₂0

H₀:₁₂< 0

H_a:₁₂= 0

H₀:₁₂0

H_a:₁₂> 0

H₀:₁₂0

H_a:₁₂< 0

H₀:₁₂0

H_a:₁₂= 0

Calculate the test statistic. (Round your answer to two decimal places.)

Calculate thep-value. (Round your answer to four decimal places.)

p-value =

What is your conclusion?

Reject H₀. There is insufficient evidence to conclude that the customer service has improved for Company B.

Do not reject H₀. There is sufficient evidence to conclude that the customer service has improved for Company B.

Do not reject H₀. There is insufficient evidence to conclude that the customer service has improved for Company B.

Reject H₀. There is sufficient evidence to conclude that the customer service has improved for Company B.

(d)

When conducting a hypothesis test with the values given for the standard deviation, sample size, and, how large must the increase from year 1 to year 2 be for it to be statistically significant? (Round your answer to two decimal places.)

(e)

Use the result of part (d) to state whether the increase for Company C from year 1 to year 2 is statistically significant.

The increase from Year 1 to Year 2 for Company C---Select---isis notstatistically significant.