Find the average of -25,-70,15,-31,-25,40

Given the following sampling distribution of one mean with a sample size 49, from a normally distributed population,find the population standard deviation, o.79828588912497

The base of a triangle exceeds the height by 9 inches. if the area is 180 square inches, find the length of the base and the height of the triangle.

To solve the system of equations below, pedro isolated the variable y in the first equation and then substituted it into the second equation. what was the resulting equation? { 5y=10x {x^2+y^2=36