Chapter 9, Problem 12SE

Babies’ Weights, Again 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. In the given outputs, the shaded areas (reported as $\text{p}=$ ) represent the probability that the mean will be larger than 7.6 or smaller than 6.4. One of the outputs uses a sample size of 4, and one uses a sample size of 9.

a. Which is which, and how do you know?

b. These graphs are made so that they spread out to occupy the room on the face of the calculator. If they had the same horizontal axis, one would be taller and narrower than the other. Which one would that be, and why?