The IRS is interested in the number of individual tax forms prepared by small accounting firms. The IRS randomly sampled 50 public accounting firms with 10 or fewer employees in the Dallas–Fort Worth area. The following frequency table reports the results of the study. Assume the sample mean is 44.8 clients and the sample standard deviation is 9.37 clients. Is it reasonable to conclude that the sample data are from a population that follows a normal probability distribution? Use the .05 significance level.

Number of Clients Frequency

20 up to 30 ........... 1

30 up to 40 ...........15

40 up to 50 ...........22

50 up to 60 ........... 8

60 up to 70 ........... 4