15. 1/2 base * hight , 1/2 * 11 * 6 = the answer is 33 cm^2
16. The "median" is the "middle" value in the list of numbers. To find the median, your numbers have to be listed in numerical order from smallest to largest, so you may have to rewrite your list before you can find the median. So the answer is 155.
17. The mean is the usual average, so I'll add and then divide. (33+25+42+25+31+37+46+29+38) / 9 = 34
18. You have to draw a plot.
