Question 910306
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Hi
Expected = {{{.10*4 + .30*3 + .40*2 + .10*1 + .10*0}}} = 2.2, C the expected grade
2.2 the mean in calculating the variance.

n	p	np	n-2.2	(n-2.2)^2
4	0.1	0.4	1.8	3.24
3	0.3	0.9	0.8	0.64
2	0.4	0.8	-0.2	0.04
1	0.1	0.1	-1.2	1.44
0	0.1	0	-2.2	4.84
		2.2		10.2 variance