1. The length of time a particular smartphone's battery lasts follows an exponential distribution with a mean of ten months. A sample of 64 of these smartphones is taken.

What is the distribution for the total length of time 64 batteries last?

N(600,85)

N(640,80)

N(700,95)

N(500,50)

cannot be determined

2. Suppose that the distance of fly balls hit to the outfield (in baseball) is normally distributed with a mean of 250 feet and a standard deviation of 50 feet. We randomly sample 49 fly balls.

If Xbar = average distance in feet for 49 fly balls, what is the distribution ofXbar?

N(250,50/rootover49)

N(250,50/rootover7)

N(250,250/rootover49)

N(150,50/rootover49)