Question

Question 2

Raw data: 19 14 25 17 29 24 36 23 9 26 22 31 19 28 8

2.1 Group the data into a frequency distribution with a lowest class lower limit of 8 and class width of 7, then draw an ogive curve and use it to estimate the mean

Answer 1

Frequency distribution table

Class	Frequency	Cumulative frequency
8-15	2	2
15-22	4	6
22-29	6	12
29-36	2	14
36-43	1	15

The first coordinate in the plot always starts at a y-value of 0 because we always start from a count of zero. So, the first coordinate is at (8,0) . The second coordinate is at the end of the first interval (which is also the beginning of the second interval) and at the first cumulative count, so (15,2) . The third coordinate is at the end of the second interval and at the second cumulative count, namely (22,6) , and so on.

X- axis	Cumulative frequency (as Y - axis)
8	0
15	2
22	6
29	12
36	14
43	15

For finding the Median

The value N / 2 = 15 /2 = 7.5 is marked on y-axis and a line parallel to x-axis is drawn .The line meets the curve at the point p . From p draw a perpendicular pr to meet x-axis at median .Therefore median = 23