US consumers are increasingly using debit cards as a substitute for cash and checks. From a sample of 100 consumers, the average amount annually spent on debit cards is $7,790. Assume that this average was based on a sample of 100 consumers and that the population standard deviation is $500. A. At 99% confidence, what is the margin of error?
B. Construct the 99% confidence interval for the population mean amount spent annually on a debit card.

A. Margin of error = 128.79

B. The 99% confidence interval for the population mean is (7661.21, 7918.79).

Step-by-step explanation:

We have to calculate a 99% confidence interval for the mean.

The population standard deviation is know and is σ=500.

The sample mean is M=7790.

The sample size is N=100.

As σ is known, the standard error of the mean (σM) is calculated as:

The z-value for a 99% confidence interval is z=2.576.

The margin of error (MOE) can be calculated as:

Then, the lower and upper bounds of the confidence interval are:

The 99% confidence interval for the population mean is (7661.21, 7918.79).

when rotating a figure 180 degrees, imagine that you are able to take the figure and turn it clockwise or counterclockwise around a center point. to rotate a figure 180 degrees, you will need to apply the rule (x, y) → (-x, -y). start by using a coordinate grid with coordinates for each vertex of the figure. the center point of the coordinate grid is located at (0, 0), which is what you will rotate the figure around. write down the original coordinates of the shape you are going to rotate. then, apply the rule. for example, coordinate (1, 2) becomes (-1, -2). another example would be, coordinate (-4, -2) becoming (4, 2). after you change each original coordinate to the rotated coordinate, you will draw your new figure.

step-by-step explanation:

answer: your correct answer is b. d.

step-by-step explanation: