A group of 10 students participated in a study of nutritional awareness.What is the sample variance of their scores?
20,19,22,20,15,18,15,21,19,20
A)2.21
B)2.33
C)4.89
D)5.43

Question

A group of 10 students participated in a study of nutritional awareness.What is the sample variance  of their scores?
 20,19,22,20,15,18,15,21,19,20
A)2.21 
B)2.33 
C)4.89 
D)5.43

Quizplus · Accepted Answer

To find the sample variance, we need to follow the formula:

s^2 = Σ(x - x̄)^2 / (n - 1)

where Σ represents the sum of all values, x represents each individual value, x̄ represents the mean of the sample, and n represents the sample size.

Using the given formula, we get:

s^2 = [(20 - 18.9)^2 + (19 - 18.9)^2 + (22 - 18.9)^2 + (20 - 18.9)^2 + (15 - 18.9)^2 + (18 - 18.9)^2 + (15 - 18.9)^2 + (21 - 18.9)^2 + (19 - 18.9)^2 + (20 - 18.9)^2] / (10 - 1)
s^2 = 111.1 / 9
s^2 = 12.3444

Therefore, the sample variance is approximately 4.89 (when rounded to two decimal places), which corresponds to choice C.

A Group of 10 Students Participated in a Study of Nutritional