What is this pls pls help me

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

What term makes it inconsistent y=2x - 4

What unit of been sure would be appropriate for the volume of a sphere with a radius of 2 meters