Answer:
Each section below
Explanation:
(a) Add all frequencies together = 200, then add 1 and divide by 2 = 100.5, lastly you need to add each frequency until you find the interval that contains the 100th and 101st height.
23+47 = 70
70+45 = 115 -> so the answer is 10<h<13
(b) Step 1: find the midpoint of each interval (upper limit+lower limit then divide by 2)
(2+6)/2 = 4
(6+10)/2 = 8
(10+13)/2 = 11.5
(13+17)/2 = 15
(17+19)/2 = 18
(19+20)/2 = 19.5
Step 2: multiply the midpoint of each interval with it's frequency
4*23 = 92
8*47 = 376
11.5*45 = 517.5
15*38 = 570
18*32 = 576
19.5*15 = 292.5
Step 3: add all of the above and divide it by the total frequency
92+376+517.5+570+576+292.5 = 2424
2424/200 = 12.12 (this is your answer to part b)
Hope this helped :)