Question

Find the variance. Round to the nearest tenth.

6, 6, 7, 17, 20, 20

A) 6.4
B) 41.2
C)12.7
D) 1.6

Answer 1

B) 41.2

Explanation:

Answer 2

41.2 to the nearest tenth.

Explanation:

There are a total of 6 numbers.

So the mean m is (6 + 6 + 7 + 17 + 20 + 20) / 6

= 76/6

= 12.67.

Calculating x - m :

6 - 12.67 = -6.67

6 - 12.67 = -6.67

7 - 12.67 = - 5.67

17 - 12.67 = 4.33

20 - 12.67 = 7.33

20 - 12.67 = 7.33

Now squaring each of these we get (x - m)^2 = 44.49, 44.49, 32.15, 18.75,

53.73, 53.73

Now the sum of these ∑(x - m)^2 = 247.34

So the variance = ∑ [(x - m)^2] / 6

= 247.34 / 6

= 41.2 to the nearest tenth.