Question

In​ Louisiana, the average weight of an adult allegator is 790​ pounds, with standard deviation of 200 pounds. What is the probability that the average wieght of a sample​(of adults​ allegators) of size 100 will be grater than 820​ pounds?

A.0.06

B.0.07

C.0.93

D.0.90

E.0.05

Answer 1

Solution :

Given that ,

mean = = 790

standard deviation = = 200

n = 100

= 790

= / n = 200 / 100 = 200 / 10 = 20

P(​ > 820) = 1 - P( < 820) = 1 - P(( - ) / < (820 -790) / 20) = 1 - P(z < 1.5)

    Using standard normal table,

P( > 820) = 1 - 0.9332 = 0.0668

Probability = 0.0668 = 0.07

Option B) is correct .