Can y’all help me on question and 19?!

For which pair of functions is (gof)(a)=|a|-2?

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

Given sin28.4=.4756, cos28.4=.8796, and tan28.4=.5407 find the cot of 61.6