Question

scores on the GBE are normally distributed with a mean of 562 and a standard deviation of 71. Use the 68-95-99.7 rule to find the percentage of people taking the test who score between 349 and 562

Answer 1

what you need to do is find out how many std. devs from the mean each score is and then apply the rule.

do you know how to compute how many std devs a score is from the mean?

Answer 2

no im not good at it

Answer 3

sorry my computer glitched

Answer 4

its fine

Answer 5

this is a (bad) drawing of the normal curve.

the empirical rule states that 68% of the data lies within 1 standard deviation (std dev) of the mean.
that means 1 std dev above and 1 std dev below.

the empirical rule states that 95% of the data lies within 2 standard devs of the mean.
that means 2 std devs above and 2 std devs below.

the empirical rule states that 99.7% of the data lies within 3 standard devs of the mean.
that means 3 std devs above and 3 std devs below.

I broke up each section to show how much is in each piece.

all that is required now is to find out how many std devs each data point is away from the mean.