Problem #5: (8 points)
1 answer:
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Answer:
A = 82.82
B = 72.53
C = 61.58
D = 53.55
Step-by-step explanation:
First, determine the percentile at which the cutoff grade in each letter grade interval falls on and find the equivalent z-score:
A: (100-10) = 90-th percentile
z-score = 1.282
B: (100-10-30) = 60-th percentile
z-score = 0.253
C : (100-10-30-40) = 20-th percentile
z-score = -0.842
D: (100-10-30-40-15) = 5-th percentile
z-score = −1.645
The value 'X' for each cutoff can be found by applying the z-score equation:
Where μ is the mean and SD is the standard deviation
Therefore, the cutoffs are: