X^3-3x^2+2x-6/x^2+3x-1

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.

Aiden buys two bags of chips at $1.09 each and a 20 ounce soda for $1.20 at the gas station. he knows that the state tax is 5.5. how much change will he receive from a $5 bill?

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?