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
Answer:
The definition of a z-score is:
z = (X - μ)/σ where X is our given score (33), μ is the distribution's mean (40) and σ is the distribution's standard deviation (9).
To calculate the z-score for 33, plug the numbers in:
z = (33 - 40)/9 = -7/9 = -.78
Hope this helps!
Step-by-step explanation:
Answer: False
Step-by-step explanation:
