Question

Refer to the Exhibit Student Grades. The professor has informed the class that 7.93 percent of her students received grades of A. What is the minimum score needed to receive a grade of A

Answer 1

This question is incomplete, the complete question is;

Refer to the Exhibit Student Grades. A professor at a local university noted that the grades of her students were normally distributed with a mean of 73 and a standard deviation of 11.

The professor has informed the class that 7.93 percent of her students received grades of A. What is the minimum score needed to receive a grade of A

Answer:

the minimum score needed to receive a grade of A is 88.51

Step-by-step explanation:

Given the data in the question;

Let x represent the grades of the students that were normally distributed with mean μ = 73 and standard deviation σ = 11.

so, The professor has informed the class that 7.93 percent of her students received grades of A

the minimum score needed to receive a grade of A will be:

P( X > x ) = 7.93 %

P( X > x ) = 0.0793

1  - P( X ≤ x ) = 0.0793

- P( X ≤ x ) = 0.0793 - 1

- P( X ≤ x ) = - 0.9207

P( X ≤ x ) = 0.9207

⇒ P( X-μ/σ ≤ x-μ/σ ) = 0.9207

so, x-μ/σ = InvNormal( 0.9207 )  

x-μ/σ = 1.41

(x - 73) / 11 = 1.41

(x - 73) = 1.41 × 11

(x - 73)  = 15.51

x = 15.51 + 73

x = 88.51

Therefore, the minimum score needed to receive a grade of A is 88.51