Question

If 54% of all people between the ages of 35 and 50 ride a bike, find the probability for a sample of 30 people in that age group exactly 15 ride a bike

Answer 1

The probability is 0.1312

Explanation:

Here, let us set up a binomial system

From the question, 54% ride a bike

Let p = people that rides a bike

54% = 54/100 = 0.54

p = 0.54

q = 1 - p = 1 -0.54 = 0.46 ( 46% do not ride bikes)

Now, for the binomial system, we have

P(X = 15) = 30 C 15 • p^15•q^15

We have;

30 C 15 * 0.54^15 * 0.46^15

= 0.131200268998

The probability is 0.1312