The ap statistics exam, like all other ap exams, is graded on a 5, 4, 3, 2, 1, 0 basis. many colleges require a 4 or a 5 to grant credit. in 1999, 25,240 students took the exam, and 30.4% of these received either a 4 or a 5. assume that the raw scores were approximately normally distributed with a mean of 60 and a standard deviation of 19. what is the minimum score a student must receive to earn a 4 or a 5?

a.70
b.71
c.72
d.69
e.68

A minimum score of 70 is required for a student to earn a 4 or a 5.

Step-by-step explanation:

We are given the following information in the question:

Mean, μ = 60

Standard Deviation, σ = 19

We are given that the distribution of raw scores is a bell shaped distribution that is a normal distribution.

Formula:

Top 30.4% students received either a 4 or a 5. Let x denotes the score that separates top 30.4% students from lowest 69.6% students

We have to find the value of x such that the probability is 0.304

P(X > x)  

Calculation the value from standard normal z table, we have,  

A minimum score of 70 is required for a student to earn a 4 or a 5.