Answer: Tim weighs 90 lbs and his brother weighs 130 lbs
No you add them all together and then you divide the number of GPA's to get the mean. You go from greatest to lowest to figure out the median and to find the mode excepts my mind. <span />
Answer:
You do (Keep, Change, Flip)
so you keep 9/4
Then change the division sign to multiplication sign
Finally flip the next fraction (10/3) becomes 3/10
9/4 * 3/10 = (9*3)/(4*10) = 27/40