The probability distribution for the rate of return on an investment is

Rate of Return
(In Percent) Probability
9.5 .1
9.8 .2
10.0 .3
10.2 .3
10.6 .1

a. What is the probability that the rate of return will be at least 10%?
b. What is the expected rate of return?
c. What is the variance of the rate of return?

a)0.7

b) 10.03

c)  0.0801

Step-by-step explanation:

Rate of return   Probability

9.5                           0.1

9.8                           0.2

10                             0.3

10.2                          0.3

10.6                          0.1

a.

P(Rate of return is at least 10%)=P(R=10)+P(R=10.2)+P(R=10.6)

P(Rate of return is at least 10%)=0.3+0.3+0.1

P(Rate of return is at least 10%)=0.7

b)

Expected rate of return=E(x)=sum(x*p(x))

Rate of return(x)   Probability(p(x))    x*p(x)

9.5                           0.1                       0.95

9.8                           0.2                      1.96

10                             0.3                        3

10.2                          0.3                        3.06

10.6                          0.1                       1.06

Expected rate of return=E(x)=sum(x*p(x))

Expected rate of return=0.95+1.96+3+3.06+1.06=10.03

c)

variance of the rate of return=V(x)=

Rate of return(x)   Probability(p(x))    x*p(x)    x²*p(x)

9.5                           0.1                       0.95       9.025

9.8                           0.2                      1.96         19.208

10                             0.3                       3             30

10.2                          0.3                       3.06        31.212

10.6                          0.1                       1.06         11.236

sum[x²*p(x)]=9.025+19.208+30+31.212+11.236=100.681

variance of the rate of return=V(x)=sum(x²*p(x))-[sum(x*p(x))]²

variance of the rate of return=V(x)=100.681-(10.03)²

variance of the rate of return=V(x)=100.681-100.6009

variance of the rate of return=V(x)=0.0801

y=mx+