What is the total number of units in millions of electricity produced each year based on the current extraction rates of coal from all mines combined assuming all mines have an endless supply of coal

Let the mean of the population be 38 instances of from 6" - 9" hatchings per nest, and let the standard deviation of the mean be 3. what sample mean would have a confidence level of 95% or a 2.5% margin of error?

How do you find principle and simple interest

What are the solutions of the system? solve by graphing. y = -x^2 - 3x + 2 y = -2x + 2