The population of a small town increased by 25% two years ago and then decreased by 25% last year. now the population is 4500 people. what ws the population before the two changes.

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.

Which expression gives you the distance between the points (5,1)and(9,-6)

The surface area of the triangular prism is .