Question

A set of data has a normal distribution with a mean of 5.1 and a standard deviation of 0.9. Find the percent of data between 6.0 and 6.9.

a.about 34%
b.about 68%
c.about 16%
d.about 13.5%

Answer 1

the empirical rule will be useful here as well:

first determine the number of standard deviation for each value:

(x-mean)/sd

(6.0-5.1)/.9
and
(6.9-5.1)/.9

Answer 2

1
2

Answer 3

good, the empirical rule gives us 68 for 1 sd, and 95 for 2 sd