Find the unknown measures. Round lengths to the nearest hundredth and angle measures to the nearest degree. Please explain too!

What two criteria are needed for triangles to be similar

Just tell me how to set up the equation.

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