20.41 is what the correct answe
Answer:
a) P ( 3 ≤X≤ 5 ) = 0.02619
b) E(X) = 1
Step-by-step explanation:
Given:
- The CDF of a random variable X = { 0 , 1 , 2 , 3 , .... } is given as:
Find:
a.Calculate the probability that 3 ≤X≤ 5
b) Find the expected value of X, E(X), using the fact that. (Hint: You will have to evaluate an infinite sum, but that will be easy to do if you notice that
Solution:
- The CDF gives the probability of (X < x) for any value of x. So to compute the P ( 3 ≤X≤ 5 ) we will set the limits.

- The Expected Value can be determined by sum to infinity of CDF:
E(X) = Σ ( 1 - F(X) )

E(X) = Limit n->∞ [1 - 1 / ( n + 2 ) ]
E(X) = 1
Answer:
arccsc(x)=1/cos(x)
Step-by-step explanation:
Answer:
d) 303 8/9
Step-by-step explanation:
4th term = ar^3 and 5th = ar^4 where a = first term and r = common ratio.
So ar^4 / ar^3
= r = 45/-15 = -3.
Working back,:
The first term a = ar^3/ r^3
= -15 / (-3)^3
= -15/-27
= 5/9
Sum of n terms = a * (r^n - 1)/(r-1)
= 5/9 * ((-3)^7 - 1 ) / (-3 -1)
= 303 8/9