How many solutions does x^2=4x-5 have?

The brain volumes (cm cubed) of 50 brains vary from a low of 904 cm cubed to a high of 1488 cm cubed. use the range rule of thumb to estimate the standard deviation s and compare the result to the exact standard deviation of 175.5 cm cubed, assuming the estimate is accurate if it is within 15 cm cubed

With number 11 ( show how you got the answer)

Find the scale factor and ratio of perimeters for a pair of similar trapezoids with areas 49 cm squared and 36 cm squared.