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Joint Destiny - Random Variable

Two different problems below:

#1.) The following is the joint density for two random variables, X1 and X2:

f(X1, X2): {3X1 for 0<=X2<=X1<=1
0 elsewhere

Find P(0.2<=X2<=0.4)

Which of the following answers:

a.) 0.3750

b.) 0.2720

c.) 0.1800

d.) 0.3(1- X1)^2

#2) Let X be a normal random variable with mean (mew) and std. dev., let
W=(X-mew/std. dev.)^2, Then the distribution for W is :

Which one?

a.) N(mew^2,check mark std, dev.)

b.) N(mew^2, std. dev.^2)

c.) N(check mark mew, std. dev.^2)

d.) X^2(1)

Solution Summary

Two different problems below:

#1.) The following is the joint density for two random variables, X1 and X2:

f(X1, X2): {3X1 for 0<=X2<=X1<=1
0 elsewhere

Find P(0.2<=X2<=0.4)

Which of the following answers:

a.) 0.3750

b.) 0.2720

c.) 0.1800

d.) 0.3(1- X1)^2

#2) Let X be a normal random variable with mean (mew) and std. dev., let
W=(X-mew/std. dev.)^2, Then the distribution for W is :

Which one?

a.) N(mew^2,check mark std, dev.)

b.) N(mew^2, std. dev.^2)

c.) N(check mark mew, std. dev.^2)

d.) X^2(1)

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