Simplify 7 -5/6 × 7 -7/6

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?

Jackie purchased 3 bottles of water and 2 cups of coffee for the family for $7.35. ryan bought 4 bottles of water and 1 cup of coffee for his family for 7.15. how much does each bottle of water cost? how much does each cup of coffee cost?