Question

The mean IQ score of students in a particular class is 110, with a standard deviation of 5. Use the 68-95

99.7 Rule to find the percentage of students with an IQ above 120?.
A) 15.85%.
B) 11.15%.
C) 13.5%.
D) 2.5%.

Answer 1

D) 2.5%.. The percentage of students with an IQ above 120 is approximately 2.5%.

Step-by-step explanation:

In this problem, we are given the mean IQ score of students in a particular class as 110, with a standard deviation of 5. We are asked to find the percentage of students with an IQ above 120 using the 68-95-99.7 Rule.

The 68-95-99.7 Rule tells us that in a normal distribution, approximately 68% of the data falls within one standard deviation of the mean, 95% falls within two standard deviations, and 99.7% falls within three standard deviations.

Since the mean IQ score is 110 and the standard deviation is 5, we can calculate the z-score for an IQ score of 120 as (120 - 110) / 5 = 2. This means that the IQ score of 120 is 2 standard deviations above the mean.

According to the 68-95-99.7 Rule, the percentage of students with an IQ above 120 is approximately 2.5%.