The weights (x) of 300 adult males were determined and used to test the hypothesis that the weights are normally distributed with a mean of 160 lb and a standard deviation of 15 lb. The data were grouped into the following classes.

Using the normal tables, the percentages for the classes are 2.28%, 13.59%, 34.13%, 34.13%, 13.59%, and 2.28%, respectively. Do the observed data show significant reason to discredit the hypothesis that the weights are normally distributed with a mean of 160 lb and a standard deviation of 15 lb? Use a = 0.05
a. Verify the percentages for the classes.
b. Solve using the p-value approach.
c. Solve using the classical approach.

Transcribed Image Text:

Observed Frequency Weight Weight (x) x 130 130 s x 145 145 x160 7 160 sx<175 38 175 sx< 190 100 90 and over Observed Frequency 102 40 13