The mean IQ score of adults is 115 , with a standard deviation of 15 . Use the Empirical Rule to find the percentage of adults with scores between 85 and 145. (Assume the data set has a bell-shaped distribution.)
$99.7 \%$
$95 \%$
$100 \%$

Step 1 ：The problem provides the mean IQ score of adults as 115, with a standard deviation of 15. We are asked to find the percentage of adults with scores between 85 and 145, assuming the data set has a bell-shaped distribution.

Step 2 ：We can use the Empirical Rule, also known as the 68-95-99.7 rule, to solve this problem. This rule states that for a normal distribution, nearly all of the data will fall within three standard deviations of the mean. Specifically, 68% of data falls within the first standard deviation from the mean, 95% fall within two standard deviations, and 99.7% fall within three standard deviations.

Step 3 ：In this case, the range of scores we are interested in is from 85 to 145. This range is 2 standard deviations away from the mean (since \(115 - 2*15 = 85\) and \(115 + 2*15 = 145\)).

Step 4 ：Therefore, according to the Empirical Rule, approximately 95% of adults have IQ scores within this range.

Step 5 ：So, the final answer is \(\boxed{95 \%}\).