The scores of a given test were normally distributed with a mean of 82. If James received a 67 with a z-score of -2.5, what is the standard deviation?

Question

asked Dec 24, 2021 157k views

1 Answer

Maxxx · Answer 1 · 2021-12-29T03:06:39+0000

Answer:

The standard deviation is 6

Explanation:

The scores of a given test were normally distributed with a mean of 82.

$\mu = 82$

James received a 67 with a z-score of -2.5

Z score = -2.5

$\bar{x}=67$

Formula :
$Z=(x-\mu)/(\sigma)$

$-2.5=(67-82)/(\sigma)$

$\sigma = (67-82)/(-2.5)$

$\sigma =6$

Hence The standard deviation is 6