a teacher has given a test to a group of students. the set of scores is: 78, 79, 79, 81, and 83. find the variance for this samp

Question

2 years ago

11

le of tests. a. 2.24 b. 6 c. 4

1 answer:

Delvig [45] · Answer 1 · 2023-06-28T11:22:11+03:00

Based on the data set, the variance for this sample of tests is 4

<h3>How to find the variance for this sample of tests?</h3>

The sample of test is given as:

78, 79, 79, 81, and 83.

Calculate the mean, using:

Mean = Sum/Count

So, we have

Mean = (78 + 79 + 79 + 81 + 83)/5

Evaluate

Mean = 80

The variance is calculated as

$\sigma^2 = \frac{\sum(x - \bar x)^2}{n-1}$

This gives

$\sigma^2$ = [(78 - 80)^2 + (79 - 80)^2 + (79- 80)^2 + (81- 80)^2 + (83- 80)^2)]/[5 - 1]

Evaluate the numerator and the denominator.

So, we have:

$\sigma^2$ =16/4

Evaluate the quotient

$\sigma^2$ = 4

Hence, the variance for this sample of tests is 4