Question

Using the 68-95-99.7rule. Assume that a set of test scores is normally distributed with a mean of 80 and a standard deviation of 25. Use the 68-95-99.7 rule to find the following quantities. percentage of scores greater than 105 is

Answer 1

a score of 105 is one standard deviation above the mean

the rule says that 68% of a normally distributed population lies within one standard deviation of the mean...half above the mean and half below

so 34% are within one standard deviation above the mean

this means that 16% are above that value

Answer 2

Assume that a set of test scores is normally distributed with a mean of 110 and a standard deviation of 20. Use the​ 68-95-99.7 rule to find the following quantities.
a. The percentage of scores less than is
nothing​110%=
​(Round to one decimal place as​ needed.)