Question

The scores of adults on an IQ test are approximately Normal with mean 100 and standard deviation 15 . Alysha scores 128 on such a test. Alysha scores higher than what percentage of adults?

Answer 1

To find out what percentage of adults Alysha scores higher than on the IQ test, we need to calculate the z-score of her score and then find the percentage of scores that are below that z-score. Alysha scores higher than approximately 96.85% of adults.

Step-by-step explanation:

To find out what percentage of adults Alysha scores higher than on the IQ test, we need to calculate the z-score of her score and then find the percentage of scores that are below that z-score.

First, we calculate the z-score using the formula: z = (x - μ) / σ, where x is Alysha's score, μ is the mean, and σ is the standard deviation.

Using the given values, Alysha's z-score is z = (128 - 100) / 15 = 1.87. We can then use a normal distribution table or calculator to find the percentage of scores below 1.87, which is approximately 96.85%. Therefore, Alysha scores higher than approximately 96.85% of adults.