21. Normal Distribution? continued Assume that the chest measurements in Exercise 20 are normally distributed with a mean of m 539.83 and a standard deviation of s 52.05.

a. What proportion of the observations would lie between 36.5 and 43.5 inches?

b. Between what two measurements would 95% of the observations lie?

c. What are the actual proportions for parts a and b using the data directly? Comment on the accuracy of the proportions found using assumed normality of the chest measurements