The 85th percentile of a normal distribution is the score that is greater than or equal to 85% of the scores in the distribution. This means that the score at the 85th percentile is the same as the score that would be earned by the top 15% of individuals in the distribution.
To find the score at the 85th percentile, we can use the standard normal distribution table or use a calculator to find the z-score corresponding to the 85th percentile. The z-score is the number of standard deviations that a score is above or below the mean of the distribution.
Using a calculator or table, we find that the z-score corresponding to the 85th percentile is 1.04. Since the mean of the distribution is 100 and the standard deviation is 15, this means that the score at the 85th percentile is 100 + (1.04 * 15) = 120.4.
Therefore, the score of an individual who is at the 85th percentile on the Weshcler IQ test is 120.4.