Question

When an automobile is stopped by a roving safety patrol, each tire is checked for tire wear, and each headlight is checked to see whether it is properly aimed. Let X denote the number of headlights that need adjustment, and let Y denote the number of defective tires.

(a) If X and Y are independent with p_X(0) = 0.5, p_X(1) = 0.3, p_X(2) = 0.2, and p_Y(0) = 0.1, p_Y(1) = 0.2, p_Y(2) = p_Y(3) = 0.05, p_Y(4) = 0.6, display the joint pmf of (X, Y) in a joint probability table.

		y
p(x, y)		0	1	2	3	4
x	0
	1
	2

(b) Compute P(X ≤ 1 and Y ≤ 1) from the joint probability table.
P(X ≤ 1 and Y ≤ 1) =  

Does P(X ≤ 1 and Y ≤ 1) equal the product P(X ≤ 1) · P(Y ≤ 1)?

YesNo    

(c) What is P(X + Y = 0) (the probability of no violations)?
P(X + Y = 0) =  

(d) Compute P(X + Y ≤ 1).
P(X + Y ≤ 1) =

Answer 1