A random sample of n measurements was selected from a population with unknown mean μ and known standard deviation σ. Calculate a 95% confidence interval for μ for the given situation. Round to the nearest hundredth when necessary. n = 125, x-bar = 91, σ = 20 Group of answer choices

The 95% confidence interval for μ for the given situation is between 87.49 and 94.51.

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 the margin of error 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 91 - 3.51 = 87.49

The upper end of the interval is the sample mean added to M. So it is 91 + 3.51 = 94.51

The 95% confidence interval for μ for the given situation is between 87.49 and 94.51.

c

step-by-step explanation:

sina-sinb

cosb+cosa

tana-tanb

cos0+cos x pi/3

20tan

step-by-step explanation: