The back to back stem and leaf plot below show exam scores from two different math classes. which class has a greater mean score? which class has a greater median score?

What are the relative frequencies, to the nearest hundredth, of the rows of the two-way table? group 1: a 15 b 45 group 2: a 20 b 25

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

Two times a number plus three times another number equals 4. three times the first number plus four times the other number is 7. find the numbers