The manager of a grocery store has selected a random sample of 100 customers. The average length of time it took these 100 customers to check out was 3.0 minutes. It is known that the standard deviation of the checkout time is 1 minute. Refer to Exhibit 8-2. If the confidence coefficient is reduced to .80, the standard error of the mean . a. becomes negative b. remains unchanged c. will increase d. will decrease

b. remains unchanged

Step-by-step explanation:

Formula for standard error of mean is;

SE = σ/√n

From the above, we can see that the standard error of mean is independent of the confidence coefficient as it doesn't affect the SE.

Now, we are given that;

random sample; n = 100

Standard deviation; σ = 1

Thus;

SE = 1/√100

SE = 1/10

Now, even if the confidence coefficient is reduced, we can see that it has no impact on the standard error of mean.

Thus, SE remains unchanged.

the figures below are made out of circles, semicircles, quarter … find the area and the perimeter of each figure and give your answers as a completely simplified exact value in terms of π (no approximations). remember that we'll also have to cut whatever areas we get in half, since we're only dealing

step-by-step explanation:

step-by-step explanation:

i believe its "c" because all of the other options include a but it could be d because there is a way of financing with cash at certain places but its uncommon.