A game of chance offers the following odds and payoffs. Each play of the game costs $100, so the net profit per play is the payoff less $100. (there are 4 answers total)

Probability	Payoff	Net Profit
0.10	$800	$700
0.50	100	0
0.40	0	?100

a-1.	What is the expected cash payoff?

Expected cash payoff

?$

a-2.	What is the expected rate of return?

Expected rate of return

?%

b-1.	Calculate the variance of this rate of return. (Round your answer to the nearest whole number.)

Variance ?

b-2.	Calculate the standard deviation of this rate of return. (Round your answer to the nearest whole percent.)

Standard deviation

?%