Question

4. [7 marks] Crave is a large subscription-based internet streaming service for movies

and television shows. Suppose the proportion of Saskatchewanians who have a Crave

subscription is 0.15. Suppose the population of Rosetown, Saskatchewan is 2700 people. What is the probability that between 14% and 17% of people in Rosetown, Saskatchewan have a Crave subscription? Round your standard deviation to 4 decimal places.

Answer 1

Solution

Given that,

p = 0.15

1 - p = 1-0.15=0.85

n = 2700

= p =0.15

=  [p ( 1 - p ) / n] = [(0.15*0.85) / 2700 ] = 0.0069

= P( 0.14 << 0.17)= P[(0.14-0.15) /0.00687 < ( - ) / < (0.17-0.15) / 0.0069]

= P( -1.46< z <3.71 )

= P(z < 3.71) - P(z < -1.46)

Using z table

=0.9992-0.0721

=0.9271

probability= 0.9271