Answer:
7.362
Explanation:
Given :
Mean = 35
Score, x value = 23
Zscore = - 1.63
Recall the Zscore formula :
Zscore = (X - mean) / standard deviation
-1.63 = (23 - 35) / standard deviation
-1.63 = - 12 / standard deviation
standard deviation * - 1.63 = - 12
Divide both sides by - 1.63
Standard deviation = - 12 / - 1.63
Standard deviation = 7.362