Question

Suppose adults in a particular town drive a mean of 65 mph with a standard deviation of 15 mph. Using the normal curve table,
a.What percentage of adults drive below 35 mph?
b.What percentage of adults drive below 68 mph or above 85 mph?
c.What percentage of adults drive between 56 and 80 mph?
d.At what speed does someone need to drive to be included in the top 10%?
e.At what speed does someone need to drive to be included in the bottom 25%?

Answer 1

a. 2.28