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

Answer:

$P(x \leq 3) = 0.8$

Step-by-step 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

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