The Rocky Mountain district sales manager of JCM, Inc., a college book publishing company, claims that each of his sales representatives makes 40 calls on professors per week. Several reps said that this estimate is too low. To research the claim, a random sample of 28 reps revealed that the mean number of calls made last week was 42. The standard deviation of the sample was computed to be 21 calls. At the .05 level of significance, can we conclude that more than 40 calls are made on the average in a week?
7. Employer A states the average number of days missed in a year by each staff member is 4.0. Office personnel randomly sampled a portion of their attendance records to determine if this claim was accurate. For the previous year, the following data was obtained from the sample group, regarding absences for that year: 4, 4, 3, 2, 6, 8, 7, 1, 9, 3, 1, and 6. At the .05 level of significance, is there convincing evidence that the number of absences per employee has increased?
8. A sample of scores on an examination given to both males and females in MAT 560 is:
Males 72, 69, 98, 66, 85, 76, 79, 80, and 77
Females 81, 67, 90, 78, 81, 80, and 76
At the .01 level of significance, is the mean grade of the female students higher than that of the males?
9. Using data from a learning team member's place of employment, prepare one problem similar to the ones above, applying the five-step hypothesis testing procedures. Use either z- or t-tests and determine standard deviations for each set of data. Be prepared to share your sample problem with the class.