Auniversity administrator expects that 25% of students in a core course will receive an a. he looks at the grades assigned to 60 students. the probability that the proportion of students that receive an a is 0.20 or less is

18.67% probability that the proportion of students that receive an a is 0.20 or less.

Step-by-step explanation:

Problems of normally distributed samples can be 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:

.

The standard deviation of a proportion is given by the following formula.

A university administrator expects that 25% of students in a core course will receive an a. There are 60 students. So and

The probability that the proportion of students that receive an a is 0.20 or less is

This is the pvalue of Z when X = 0.2. So

has a pvalue of 0.1867.

So there is an 18.67% probability that the proportion of students that receive an a is 0.20 or less.

overpriced

step-by-step explanation: