How fo I do this? please, need help​

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

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?

Are the corresponding angles congruent? explain why or why not.