Need to check an answer

What are the (a) expected return, (b) standard deviation, and (c) coefficient of variation for an investment with the following probability distribution?

probabilities: .2, .7, & .1 payoff: 19.0%, 9.0%, 4.0%

My answers

a. .2(.19)+.7(.09)+.1(.04)= 10.5

b. (.00722)+(.0081)+(.0016)= .01692= sq rt .01692 = .13 = 13%

c. .13/10.5=1.2

Thank you