Question

A TV​ show, Lindsay and Tobias​,

recently had a share of 15
​,
meaning that among the TV sets in​ use, 15
​%
were tuned to that show. Assume that an advertiser wants to verify that 15
​%
share value by conducting its own​ survey, and a pilot survey begins with 14

households having TV sets in use at the time of a Lindsay and Tobias broadcast.
a. Find the probability that none of the households are tuned to Lindsay and Tobias

Answer 1

We are given with
x = 15%
n = 14

and asked to get the probability that none are turned to the show
u = 0

Using the formula for the z-score
z = x - u / s
where x and u are given
s is supposed to be given as well

If there is a value of s, substitute the values and solve for z
Then, refer to the z-score table (one-tailed) to determine probability basin on the z-score.