Question

A local industry representative claims that 35% of all cable subscribers bundle a number of services with their cable subscription.

a) If 150 cable customers are sampled, what is the probability that fewer than 60 of the sampled customers bundle a number of services?

Answer 1

Mean = n * P = ( 150 * 0.35 ) = 52.5
Variance = n * P * Q = ( 150 * 0.35 * 0.65 ) = 34.125
Standard deviation = = 5.8417

P ( X < 60 )
Using continuity correction
P ( X < n - 0.5 ) = P ( X < 60 - 0.5 ) = P ( X < 59.5 )

P ( X < 59.5 )
Standardizing the value

Z = ( 59.5 - 52.5 ) / 5.8417
Z = 1.2

P ( X < 59.5 ) = P ( Z < 1.2 )
P ( X < 59.5 ) = 0.8849

P ( X < 60 ) = 0.8849