Question

an industry representative claim that 60% of all satellite owners subscribers movie channel. suppose that representative’s claim is true and also suppose that 20 dish owners are randomly selected. find the probability that: (i) none of the dish owners subscribes movie channel (ii) exactly 3 dish owners subscribe movie channel (iii) more than 17 dish owners subscribe movie channel.

Answer 1

1.099 * 10^-8 ; 4.23 * 10^-5 ; 0.0036

Explanation:

Given :

p = 0.6

Sample size, n = 20

P(x = 0)

Using binomial distribution formula :

P(x =x) = nCx * p^x * (1 - p)^(n - x)

1 - p = 1 - 0.6 = 0.4

P(x = 0) = 20C0 * 0.6^0 * 0.4^20

P(x = 0) = 1 * 1 * 1.099511627776E−8

P(x = 0) = 1.099 * 10^-8

2) Exactly 3;

P(x = 3) = 20C3 * 0.6^3 * 0.4^17

P(x = 3) = 1140 * 0.216 * 0.00000017179869184

P(x = 3) = 0.0000423037098786816

P(x = 3) = 4.23 * 10^-5

3.) More than 17

P(x > 17) = P(x = 18) + P(x = 19) + P(x = 20)

Using calculator :

P(x > 17) = 0.0036