Question

For each problem, select the best response.

a) The scores of adults on an IQ test are approximately normal with a mean of 100 and a standard deviation of 15. Corinne scores 118 on such a test. Her z-score is about:

a) 0.80
b) 1.20
c) 1.87
d) 2.00

Answer 1

Corinne's z-score is approximately 1.20. Option b

Step-by-step explanation:

To find Corinne's z-score, we can use the formula: z = (x - μ) / σ where x is the value of the IQ score, μ is the mean of the IQ scores, and σ is the standard deviation of the IQ scores.

Given that Corinne's score is 118, the mean is 100, and the standard deviation is 15, we can substitute the values into the formula: z = (118 - 100) / 15

Simplifying the equation gives: z = 1.2

Therefore, Corinne's z-score is approximately 1.20. Option b