Question

The Rocky Mountain district sales manager of Rath Publishing Inc., a college textbook publishing company, claims that the sales representatives make an average of 40 sales calls per week on professors. Several reps say that this estimate is too low. To investigate, a random sample of 32 sales representatives reveals that the mean number of calls made last week was 41. The standard deviation of the sample is 2.9 calls. Using the 0.010 significance level, can we conclude that the mean number of calls per salesperson per week is more than 40?

H₀: μ ≤ 40

H₁: μ > 40

1. Compute the value of the test statistic. (Round your answer to 3 decimal places.)

2. What is your decision regarding H₀?
   1. __Do not reject or Reject____ H0. The mean number of calls is__Less or Greater_____

Answer 1

Solution :

Given that,

= 40  

= 41

= 2.9

n = 32

The null and alternative hypothesis is ,

H₀ :   40

H_a : > 40

This is the right tailed test .

Test statistic = z

= ( - ) / / n

= ( 41 - 40 ) / 2.9 / 32

= 1.951

The test statistic = 1.951

P - value = P(Z > 1.951 ) = 1 - P (Z < 1.951 )

= 1 - 0.9745

= 0.0255

P-value = 0.0255

= 0.010

0.0255 > 0.010

P-value >

Fail to reject the null hypothesis .

Do not reject Ho There is not sufficient evidence to test the claim. that The mean number of calls is 40 Less or Greater > 40