The mean life expectancy of a certain type of light bulb is 895 hours with a standard deviation of 18 hours. What is the approximate standard deviation of the sampling distribution of the mean for all samples with n = 40?

Respuesta :

Answer:

The approximate standard deviation of the sampling distribution of the mean for all samples with n = 40 is 2.8460.

Step-by-step explanation:

The Central Limit Theorem estabilishes that, for a random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sample means with size n of at least 30 can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex]

What is the approximate standard deviation of the sampling distribution of the mean for all samples with n = 40?

We have that [tex]\sigma = 18[/tex]

So

[tex]s = \frac{18}{\sqrt{40}} = 2.8460[/tex]

The approximate standard deviation of the sampling distribution of the mean for all samples with n = 40 is 2.8460.