Question

Find standard deviation. (Answer format: 0.XXXX)

Probability	Ri
30%	8%
20%	10%
40%	9%
10%	11%

Answer 1

	probability	return in %	return-average return	square of (return-average return)	probability*square of (return-average return)
	0.3	8	-1.1	1.21	0.363
	0.2	10	0.9	0.81	0.162
	0.4	9	-0.1	0.01	0.004
	0.1	11	1.9	3.61	0.361
average return =(probability1*return)+(probility 2* return)+(probability 3*return)+(probability4*return)	(.3*8)+(.2*10)+(.4*9)+(.1*11)	9.1	Variance = sum of probability*square of (return-average return)		0.89	0.943398
			standard deviation = square root of variance =Using SQRT function in M s excel =sqrt(.89)		0.9433