Who has the faster training rate

Which of the following expressions are equivalent ?

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

:24% of students in a class are girls. if there are less than 30 students in this class, how many students are there? how many girls are there?