What is an expression with a negative exponent that has a value between 0 and 1/2

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

The fraction 7/9 is equivalent to a percent that is greater than 100%. truefalse

(x-5)1/2+5=2 what is a possible solution?