A sample of Geometry class final exam grades are as follows:
80, 85, 72, 76, 95
Find the variance.
1) 7.96
2) 49.23
3) 63.44
4) 6.72

Question

A sample of Geometry class final exam grades are as follows:
80, 85, 72, 76, 95
Find the variance.
	1)	7.96
	2)	49.23
	3)	63.44
	4)	6.72

amistre64 · Answer

for variance we need the mean first

anonymous · Answer

what mean means

amistre64 · Answer

$$var=\frac{\sum (x-\bar x)^2}{n-1}$$

amistre64 · Answer

your asking a question that presupposes you know what a mean is; its the average of the given data

anonymous · Answer

add it all together then divide by 5

amistre64 · Answer

yes, and that is what we use to get a final answer for variance.

amistre64 · Answer

(mean - x)^2 = (x-mean)^2

so i see no need to be strict about that part of it tho

anonymous · Answer

its 332

amistre64 · Answer

hmm, im not so sure about that, let me do some calculations in a general sense

anonymous · Answer

the answer is 49.23

amistre64 · Answer

mean = (80+85+72+76+95)/5 = 81.6

(81.6-80)^2+(81.6-85)^2+(81.6-72)^2+(81.6-76)^2+(81.6-95)^2 = 317.2

317.2/(5-1) = 79.3 as a variance

anonymous · Answer

thats not an answer choice

amistre64 · Answer

then the answer choices are wrong.

amistre64 · Answer