In the diagram, RT is a tangent to the circle at R, < PQR = 70\(^o\), < QRT = 52\(^o\), < QSR and < PRQ = x. Calculate the variance of 2, 4, 7, 8 and 9
A.
7.2
B.
6.8
C.
3.5
D.
2.6
Correct answer is B
|
x 2 4 7 8 9 |
(\(\bar{x} - \bar{x}\)) -4 -2 1 2 4 |
(\(\bar{x} - \bar{x})^2\) 16 4 1 4 9 _________ \(\sum (x - x)^2\) = 34 |
\(\bar{x} = \frac{2 + 4 + 7 + 8 + 9}{5} = 6
variance = \(\frac{34}{5}\)
= 6.8