In a study of 265 subjects, the average score on the examination was 63.8 and s = 3.08. What is a 95 percent confidence for μ?

The 95 percent confidence for μ is (63.4292, 64.1708).

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 s is the standard deviation of the population and n is the size of the sample.

The lower end of the interval is the mean subtracted by M. So it is 63.8 - 0.3708 = 63.4292

The upper end of the interval is the mean added to M. So it is 63.8 + 0.3708 = 64.1708

The 95 percent confidence for μ is (63.4292, 64.1708).

$450

step-by-step explanation:

first, you have to multiply 150x2=300

next, you have to add 150+300= 450