Question

For the data set$10,12,40,35,14,24,13,21,42,30$, find the variance.

• A. $130.69$
• B. $129.69$
• C. $131.69$
• D. None of these

Answer 1

The correct option is A $130.69$

											SUM
$X$	10	12	40	35	14	24	13	21	42	30	241
$|X-\overline{X}|$	+14.1	+12.1	+15.9	10.9	+10.1	+0.1	+11.1	+3.1	17.9	5.9	101.20
$(X-\overline{X}{)}^2$	198.81	146.41	252.81	118.81	102.01	0.01	123.21	9.61	320.41	34.81	1306.9

$\overline{X}=\frac{\sum X}{N}=\frac{241}{10}=24.1$

${\sigma }_x=\sqrt{\frac{\sum (X-\overline{X}{)}^2}{N}}=\sqrt{130.69}=11.43$

Variance $={\sigma }_x^2=130.69$