Find the variance and standard deviation for {4, 4, 4, 4, 5}

Variance = 0.16 and Standard deviation = 0.4.

Step-by-step explanation:

I am assuming you want the population variance and standard deviation.

Mean = (16+5) / 5 = 21 / 5 = 4.2.

Subtracting the mean from the values we have

4 - 4.2 = - 0.2 (4 of these)

5 - 4.2 = 0.8.

The variance is the sum of the squares of these differences / the mean:

The variance = (4 * (-0.2) ^2 + 0.8^2) / 5

= 0.8 / 5

= 0.16.

Standard deviation = sqrt 0.16 = 0.4.