In a factory that produces wire, a spooling

machine is programmed to put 3550 feet of

wire on each spool.

The company ran the machine multiple times

and recorded how much wire was actually

placed on each spool. They found that the

mean length of wire was actually 3530 feet

with a standard deviation of 20 feet. Then

they ran the machine again to produce an

additional sample of 400 spools of wire.

Assume that the data is normally distributed

and use the 68-95-99.7 Rule to answer

the following questions.

AHow many spools from the sample of 400

have more than 3550 feet of wire?

spools

BHow many spools from the sample of 400

have between 3490 and 3570 feet of wire?

spools