Question

Brianna received an overall IQ score of 117 on the Wechsler Scale. This means that Brianna has scored approximately____________ standard deviation above the mean IQ score of ____________. A. 2; 90 B. 1; 110 C. 2; 75 D. 1; 100

Answer 1

Using the normal distribution, it is found that the correct option is:

• D. 1; 100

In a normal distribution with mean $\mu$ and standard deviation $\sigma$, the z-score of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

• It measures how many standard deviations the measure is from the mean.

In this problem:

• The mean on the Wechsler Scale is of 100, hence $\mu = 100$.

• The standard deviation is of 17, hence $\sigma = 17$.

• Brianna had an score of 117, hence $X = 117$

Then:

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{117 - 100}{17}$

$Z = 1$

Hence, the option d is correct.

To learn more about the normal distribution, you can check brainly.com/question/24663213