Suppose that a, b, c, are independent random variables, each being uniformly distributed over (0, 1). (a) what is the joint cumulative distribution function of a, b, c? (b) what is the probability that all of the roots of the equation ax2 + bx + c = 0 are real?

a)  F (A , B,C)(a,b,c) = abc

b) Answer is in derivative

Step-by-step explanation:

Hence area is maximum x=6

For ( a,b,c) ∈ (0,1)

We have that      

F A, B,C (a,b,c) = A≤ a , B≤ b , C≤c

                        =P (A≤a) P (B≤b) P (C≤c)

A , B, C ≈ unit  (0,1) we have that

  P (A≤a) =a

 P (B≤b) =b

   P (C≤c)=c

Thus

F (A , B,C)(a,b,c) = abc

b) Answer is in derivative

1.true 2.false? ? i think. .

step-by-step explanation:

if you are saying purchasing 3 social media ads and one newspaper ad counts as one purchase then there are:

6 purchases

if you are asking how many of each then:

18 social media ads

6 newspaper ads