Question

on a standardized exam the scores are normally distributed with a mean of 70 and a standard deviation of 20. find the z of a person who scored 128 on the exam

Answer 1

The z-score of a person who scored 128 on the exam is equal to 2.9

What is a z-score?

A z-score is also referred to as a z-value or standard score and it can be defined as a measure of the distance between a raw score and the mean, when standard deviation units are used.

Mathematically, the z-score of a given sample score in a normal distribution can be calculated by using this formula:

$z=\frac{x\;-\;u}{\sigma}$

Where:

• x represents the sample score.
• u represents the mean score.
• σ represents the standard deviation.

Substituting the given parameters into the formula, we have;

Z-score, z = (128 - 70)/(20)

Z-score, z = 58/20

Z-score, z = 2.9

Read more on z-scores here: brainly.com/question/26714379

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