Calculate the variance of 2, 3, 3, 4, 5, 5, 5, 7, 7 and 9
A
2.2
B
3.4
D
4.0
Verified Correct Answer: D.
Step-by-Step Mathematical Solution
x = \(\frac{2 + 3 + 3 + 4 + 5 + 5+ 5+ 7 + 7 + 9}{10}\)
=\(\frac{50}{10}\)
= 5
Variance = \(\frac{\sum{(x - x})^2}{N}\)
\(\frac{9 + 4+ 4+ 1 + 4 + 4 + 16}{10}\)
= \(\frac{42}{10}\)
= 4.2
Source: Myschool Past Questions Archive (Record #50138)