Aboard is 5 3/8 inches wide. the carpenter said that this board is 2 1/4 inches too wide for the job. how wide of the board does the carpenter need?

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