Joanna purchased four boxes of cookies for a party. Each box cost $3.28, including tax. Which expression represents how to calculate the total cost of the cookies Joanna purchased? (A) 4 ÷ $3.28
(B) 4 – $3.28
(C) 4($3.28)
(D) 4 + $3.28

Describe in detail how you would construct a 95% confidence interval for a set of 30 data points whose mean is 20 and population standard deviation is 3. be sure to show that you know the formula and how to plug into it. also, clearly state the margin of error.

The length of each stair is 11 inches. what is the rise, r, for each stair? round to the nearest inch. 2 inches 7 inches 17 inches 24 inches

Find the value of p for which the polynomial 3x^3 -x^2 + px +1 is exactly divisible by x-1, hence factorise the polynomial