Question

A recent survey found that 70% of all adults over 50 wear sunglasses for driving. In a random sample of 10 adults over 50, what is the probability that at least six wear sunglasses

Answer 1

Answer:

0.8497

Step-by-step explanation:

Given that:

n = 10 ; number who wear sunglasses = atleast 6 ; proportion, p = 0.7

Using binomial probability formula :

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

P(x ≥ 6) = P(6) + P(7) + P(8) + P(9) + P(10)

To save computation time, we can use a binomial probability calculator :

P(x =6) = 0.2001

P(x = 7) = 0.2668

P(x = 8) = 0.2335

P(x = 9) = 0.1211

P(x = 10) = 0.0282

= 0.2001 + 0.2668 + 0.2335 + 0.1211 + 0.0282

= 0.8497