PLEASE HELP ME ND FAST

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

Write and solve a real word problem that involves determining distance on a coordinate plane

Which number can each term of the equation be multiplied by to eliminate the decimals before solving? 5.6j- 0.12=4+1.1j