Explosive devices used in mining operations produce nearly circular craters when detonated. The radii of these craters are exponentially distributed with mean feet. Find the mean and variance of the areas produced by these explosive devices.

Which statements describe the solutions to the inequality x< -20 check all that apply. there are infinite solutions. each solution is negative. each solution is positive. the solutions are both positive and negative. the solutions contain only integer values. the solutions contain rational number values.