About 81% of the world's population can roll their tongue. What is the probability that in a random sample of 2,000 people, more than 1,600 of them can roll their tongue?

A. 0.8729
B. 0
C. 1
D. 0.1271
E. 0.19

Respuesta :

Answer:

A. 0.8729

Step-by-step explanation:

Since the sample size is large enough (np > 10 and nq > 10), we can estimate this with a normal distribution.

μ = p

μ = 0.81

σ = √(pq / n)

σ = √(0.81 (1 − 0.81) / 2000)

σ = 0.0088

x = 1600 / 2000

x = 0.8

Find the z score:

z = (x − μ) / σ

z = (0.8 − 0.81) / 0.0088

z = -1.14

Use a calculator or table to find the probability.

P(Z > -1.14)

1 − P(Z < -1.14)

1 − 0.1271

0.8729