What is the interquartile range of 16,25,12,20,10,25

Identify an equation in point slope form for the line perpendicular to y=3x+5 that passes through (4,-1)

I’m on question 7 it says a covered water tank is in the shape of a cylinder the tank has a 28 inch diameter and a height of 66 inches to the nearest square inch what is the surface area of the water tank

Use sigma notation to represent the following series for 9 terms.