Help please will mark brainliest

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

If private savings 'v' = 0.75s and total savings 's' equals $4.20 billion, solve for public and private savings.

Find the value of x. give reasons to justify your solutions! c ∈ ae