Question

a score that is that is 4 points above the mean corresponds to a z-score of z = 0.50. what is the standard deviation?

Answer 1

8

Explanation:

formula for finding z-scores including standard deviation, mean and 'observed value.'

X is observed value, σ is standard deviation, υ is mean.

X is 4 more than mean, so X = υ + 4

formula is z = (X - υ) / σ

0.50 = ((υ + 4) - υ) / σ = 4/σ

so we have 0.50 = 4/σ

0.50σ = 4

σ = 4/0.50

= 8