Question

Standardized​ exam's scores are normally distributed. In a recent​ year, the mean test score was 21.2 and the standard deviation was 5.7 The test scores of four students selected at random are 15,23,7 and 35 . Find the​ z-scores that correspond to each value and determine whether any of the values are unusual.

The​ z-score for 15 is

Answer 1

The z-score for a test score of 15, with a mean of 21.2 and a standard deviation of 5.7, is approximately -1.09. This is within the range of usual values, since it is not less than -2 or greater than 2.

Step-by-step explanation:

To find the z-score for a given score, we use the formula:

z = (X - μ) / σ

Where:

For a score of 15, with a mean (μ) of 21.2 and a standard deviation (σ) of 5.7:

z = (15 - 21.2) / 5.7

z = -6.2 / 5.7

z = -1.09 (approximately)

The z-score for a score of 15 is approximately -1.09. A score is typically considered unusual if it has a z-score less than -2 or greater than 2.

Answer 2

32’s 21 savages lil raw jhit only