Question

A large cable company reports the following.

Answer 1

Answer:

Step-by-step explanation:

Let n(U) be total amount or customers = 100%

n(C) = 80% of its customers subscribe to its cable TV service.

n(I) = 41% of its customers subscribe to its Internet service.

n(T) = 31% of its customers subscribe to its telephone service.

n(CnI) = 25% of its customers subscribe to both its cable TV and Internet service.

n(CnT) = 20% of its customers subscribe to both its cable TV and phone service.

n(InT) = 22% of its customers subscribe to both its Internet and phone service.

n(CnInT) = 15% of its customers subscribe to all three services

number of those that subscribed to TV only = n(C) - (n(CnInT')+(n(CnI'nT)+(n(CnInT))

= 80-[(25-15)+(20-15)+15]

= 80-{10+5+15)

= 80-30

= 50

Hence 50% read cable TV only

Pr(cable TV only) = 50/100 = 1/2

2) number of people that read internet and cable TV = 25%

Pr(internet and cable) = 25/100 = 1/4

3) number of people that had exactly two services are;

n(cable and internet only)+n(internet and phone only)+(cable and phone only)

= (25-15)+(22-15)+(20-15)

= 10+7+4

= 21%

Hence 21℅ read exactly two services

pr(exactly 2 services) = 21/100

4) number of people that read internet and cable only = n(CnI) - n(CnInP)

= 25-15 = 10%

Pr(Internet and cable only) = 10/100 = 1/10