Which graph models the functions f(x)=-4(2)^x

One integer is 8 times another. if the product is 72, then find the integers

Barbara deposited $300 in the bank. if the bank pays her simple interest at the rate of 4 percent per year, how much money will she have in her account at the end of 9 months?

The standard deviation for a set of data is 5.5. the mean is 265. what is the margin of error?