A research scientist wants to know how many times per hour a certain strand of bacteria reproduces. The mean is found to be 11.4 reproductions and the population standard deviation is known to be 2. If a sample of 375 was used for the study, construct the 90% confidence interval for the true mean number of reproductions per hour for the bacteria. Round your answers to one decimal place.

The 90% confidence interval for the true mean number of reproductions per hour for the bacteria is between 11.2 and 11.6 reproductions.

Step-by-step explanation:

We have that to find our level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of .

So it is z with a pvalue of , so

Now, find M as such

In which is the standard deviation of the population and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 11.4 - 0.2 = 11.2 reproductions.

The upper end of the interval is the sample mean added to M. So it is 11.4 + 0.2 = 11.6 reproductions.

The 90% confidence interval for the true mean number of reproductions per hour for the bacteria is between 11.2 and 11.6 reproductions.

x + 4/7

step-by-step explanation:

use cymath