Using the information below, answer the questions that follow.
Miss Bridget teaches in a small learning support class. The follow are the data from a recent math assessment from three of her students: 84, 80, 74.
-What is the variance?
A) 4.11
B) 10
C) 79.33
D) 16.8889

Question

Quizplus · Accepted Answer

To find the variance, first find the mean: (84+80+74)/3 = 78
Then, find the deviation from the mean for each score: 
84-78 = 6 
80-78 = 2 
74-78 = -4 
Square each deviation: 
6^2 = 36 
2^2 = 4 
(-4)^2 = 16 
Find the average of the squared deviations: (36+4+16)/3 = 18.67
Therefore, the variance is 18.67.
The best choice is D as it is the only option that matches the calculated variance.

Using the Information Below, Answer the Questions That Follow