Question

Let X be a random variable which can take the values 0, 1, 2, 3, 4, 5, or 6. Which of the following is equal to (X≤3)?P (X= 4) + P(X = 5) + P(X= 6)P (X = 0) + P(X = 1) + P(X = 2)P (X = 3) + (P X = 4) + (P X = 5) + P(X=6)P (X = 0) + P (X = 1) + P (X = 2) + P (X = 3)

Answer 1

We are given a random variable x which can take the values:

x = {0,1,2,3,4,5,6}

And we are required to calculate P( x ≤ 3 )

(Please note the question is missing the letter P)

The probability of having an element from x that is less or equal to 3 can be calculated individually by finding the probability of all the elements less or equal to 3, that is:

P(x=0) + P(x=1) + P(x=2) + P(x=3)

Note we must include the last term because x can also have the value of 3

Answer: The last choice as shown above