+360 The graph shows a probability distribution.
Which probabilities are equal to 0.2?
Select each correct answer.
P(X≤2)
P(X≥4)
P(2≤X≤4)
P(1≤X≤3)
2.
The graph shows a probability distribution.
P(X≤a)=0.5
What is the value of a?
3.5
4
4.5
5
THAnk YoU!!!!
+128460 First one
P(X≤2) = (1/2)(2) (0.2) = 0.2
P(X≥4) = (1/2)(1)(0.4) = 0.2
P(2≤X≤4) = 1 - P(X≤2) - P(X ≥ 4) = 1 - 0.2 - 0.2 = 0.6
P(1≤X≤3) = P(X≤3) - P(X ≤1) = (1/2)(3)(0.3) - (1/2) (1) (0.1) = 0.4
Second one
a = 4
To see why......draw a vertical line at X = 4
This will form two trapezoids with bases 4 and 1 and height .20
So....the area of one of these trapezoids = (1/2)(.20) (4 + 1) = .10 * 5 = 0.5
So P(X ≤ 4) = .50
