The grade distribution for a certain class is shown in the table. Find the probability distribution associated with these data.
A)
B)
C)
D)

Question

The grade distribution for a certain class is shown in the table. Find the probability distribution associated with these data.  ​
A) ​ ​ 
B) ​ 
C) ​ 
D) ​ ​

Quizplus · Accepted Answer

To find the probability distribution, we need to divide the frequency of each grade by the total number of grades.

For example, to find the probability of receiving an A, we divide the frequency of As (10) by the total number of grades (30):

P(A) = 10/30 = 1/3

We can use the same process to find the probabilities for each grade and put them in a table:

Grade| Frequency| Probability
---|---|---
A| 10| 1/3
B| 12| 2/5
C| 6| 1/10
D| 2| 1/30

Only choice B matches this table.

The Grade Distribution for a Certain Class Is Shown in the Table