The weights of the fish in a certain lake are normally distributed with a mean of 10.1 lb and a standard deviation of 2.9 lb. If 32 fish are randomly selected, what is the probability that the mean weight will be more than 10.9 lb? Express the answer as a percentage rounded to the nearest hundredth without the % sign.

Respuesta :

Answer:  5.94%

Step-by-step explanation:

Let X be the random variable that represents the weights of the fish.

Given: Weights of the fish in a certain lake are normally distributed with a mean of 10.1 lb ([tex]\mu[/tex]) and a standard deviation of 2.9 lb ([tex]\sigma[/tex]).

sample size : n= 32

The probability that the mean weight will be more than 10.9 lb:

[tex]P(\overline{X}>10.9)=P(\dfrac{\overline{X}-\mu}{\dfrac{\sigma}{\sqrt{n}}}>\dfrac{10.9-10.1}{\dfrac{2.9}{\sqrt{32}}})\\\\=P(Z>1.56)\\\\=1-P(Z<1.56)\\\\=1- 0.9406\ \ [\text{By p-value table}]\\\\=0.0594=5.94\%[/tex]

Hence, the required probability = 5.94%.