Chapter 9, Problem 11SE

Babies Weights (Example 2) Some sources report that the weights of full-term newborn babies have a mean of 7 pounds and a standard deviation of 0.6 pound and are Normally distributed.

a. What is the probability that one newborn baby will have a weight within $0.6$ pound of the $\text{mean}-\text{that}$ is, between $6.4$ and $7.6$ pounds, or within one standard deviation of the mean?

b. What is the probability the average of four babies’ weights will be within $0.6$ pound of the $\text{mean}-\text{that}$ is, between $6.4$ and $7.6$ pounds?

c. Explain the difference between a and b.