Question

The following data were obtained from a survey of college students. The variable

X represents the number of non-assigned books read during the past six months.
x 0 1 2 3 4 5
P (X = x) 0.20 0.25 0.20 0.15 0.10 0.10

Find P(X≤3).
A.0.20.
B.0.80.
C.0.85.
D.0.15.

Answer 1

`P(x \leq 3) = 0.8`

Explanation:

We are given the following information in the question:

x: 0 1 2 3 4 5

P(X=x): 0.20 0.25 0.20 0.15 0.10 0.10

We have to find

`P(x \leq 3)\\P(x \leq 3) = \displaystyle\sum_(x=0)^(x=3) P(X=x)\\\\= P(x = 0) + P(x = 1) + P(x = 2) + P(x = 3)\\\\= 0.20 + 0.25 + 0.20 + 0.15\\= 0.8`