Question

Calculate the value of the sample variance. Round your answer to one decimal place. 9_5,9_5,2,9_5

Answer 1

Answer:

$s^2 = 0.01$

Step-by-step explanation:

Given

Values: 9/5, 9/5, 2, 9/5

Required

Calculate the sample variance

Sample variance is calculated using:

$s^2 = \frac{\sum (x_i - \overline x)^2}{n - 1}$

First, we calculate the mean

$\overline x = \frac{\sum x}{n}$

$\overline x = \frac{9/5 + 9/5 + 2 + 9/5}{4}$

$\overline x = \frac{7.4}{4}$

$\overline x = 1.85$

$s^2 = \frac{\sum (x_i - \overline x)^2}{n - 1}$ becomes

$s^2 = \frac{(9/5 - 1.85)^2+(9/5 - 1.85)^2+(2 - 1.85)^2+(9/5 - 1.85)^2}{4 - 1}$

$s^2 = \frac{(-0.05)^2+(-0.05)^2+(0.15)^2+(-0.05)^2}{4 - 1}$

$s^2 = \frac{0.0025+0.0025+0.0225+0.0025}{3}$

$s^2 = \frac{0.03}{3}$

$s^2 = 0.01$

Hence, the variance is 0.01