Question

16% of students scored higher than 80 on a recent normally distributed exam the standard deviation is 10 what is the mean

Answer 1

Answer:

70.06

Mean score = 70

Step-by-step explanation:

16% of students scored higher than 80 on a recent normally distributed exam the standard deviation is 10 what is the mean

For a normal distribution :

Zscore = (x - mean) / standard deviation

x = score

P(Z > 80) = 16% = 0.16 ; corresponding Zscore = 0.994 (Z probability calculator)

Therefore ;

0.994 = (80 - mean) / 10

0.994 * 10 = 80 - mean

9.94 = 80 - mean

Mean = 80 - 9.94

Mean = 70.06

Hence, the mean score = 70.06 = 70