Question

Suppose 50 percent of the customers at Pizza Palooza order a square pizza, 70 percent order a soft drink, and 35 percent order both a square pizza and a soft drink.
Required:
Is ordering a soft drink independent of ordering a square pizza? Explain

Answer 1

Answer:

Ordering a soft drink is independent of ordering a square pizza.

Step-by-step explanation:

20% more customers order a soft drink than pizza, therefore they cannot be intertwined.

Given: P(A)=0.5 & P(B)=.7

P(A∩B) =  P(A) × P(B)

=  0.5 × .7

=  0.35

P(A∪B) =  P(A) + P(B) - P(A∩B)

=  0.5 + .7 - 0.35

=  0.85

P(AΔB) =  P(A) + P(B) - 2P(A∩B)

=  0.5 + .7 - 2×0.35

=  0.5

P(A') =  1 - P(A)

=  1 - 0.5

=  0.5

P(B') =  1 - P(B)

=  1 - .7

=  0.3

P((A∪B)') =  1 - P(A∪B)

=  1 - 0.85

=  0.15