Marcus is comparing the costs of two cellular phone services.
1 answer:
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Answer:
27,361.
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean and standard deviation
, the zscore of a measure X is given by:
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:
Ninety-five percent of all students at private universities pay less than what amount?
This is the 95th percentile, that is, X when Z has a pvalue of 0.95. So X when Z = 1.65.
So the answer is 27,361.