In a statistics class, 10 scores were randomly selected with the following results (mean = 71.5): 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What is the variance?
A) 22.72
B) 12.00
C) 4.77
D) 516.20
E) 144.00

Question

Quizplus · Accepted Answer

(74 − 71.5) = 2.5 squared = 6.25
(73 − 71.5) = 1.5 squared = 2.25
(77 − 71.5) = 5.5 squared = 30.25
(77 − 71.5) = 5.5 squared = 30.25
(71 − 71.5) = 0.5 squared = 0.25
(68 − 71.5) = −3.5 squared = 12.25
(65 − 71.5) = −6.5 squared = 42.25
(77 − 71.5) = 5.5 squared = 30.25
(67 − 71.5) = −4.5 squared = 20.25
(66 − 71.5) = −5.5 squared = 30.25
(6.25 + 2.25 + 30.25 + 30.25 + 0.25 + 12.25 +42.25 + 30.25 + 20.25 + 30.25) = 204.5 / 9 = 22.72

In a Statistics Class, 10 Scores Were Randomly Selected with the Following