Consider the following sample:

22 46 25 37 35 84 33 54 80 37 76 34 48 86 41 13 49 45 62 47 72 70 91 51 91 43 56 25 12 65

a. Calculate the mean and standard deviation for this data.

b. Determine the percentage of data values that fall in each of the following intervals:
.

c. Compare these with the percentages that should be expected from a bell-shaped distribution. Does it seem plausible that these data came from a bellshaped population? Explain.