Question

Person number	X Value	Y Value	Person number	X Value	Y Value	Person number	X Value	Y Value
1	24	30	11	39	42	21	21	27
2	42	53	12	60	65	22	33	29
3	20	27	13	34	40	23	25	27
4	31	30	14	24	26	24	22	25
5	22	24	15	51	57	25	28	33
6	46	47	16	80	83	26	34	40
7	52	60	17	28	27	27	53	55
8	25	28	18	25	29	28	26	28
9	30	30	19	30	31	29	29	33
10	23	27	20	43	44	30	26	29

Work for the first variable, X:

2. Construct a frequency table, containing at least 5 classes, but no more than 8 classes. [2]

**Data goes up to 83**

Class	Frequency
20-29
30-39

3. Make the following graphs, using Stat Crunch.

1. histogram [2]

2. frequency polygon [2]

3. cumulative frequency polygon [2]

4. stem and leaf [2]

5. box plot [2]

Answer 1

Data for X variable has minimum value = 20

maximum value = 80

let the class interval be 10

Number of classes = (80 - 20)/10 = 6 classes we make 7 classes because maximum value is 80 which will be counted in a class of 80 - 90.

Classes	Frequency
20 - 30	15
30 - 40	7
40 - 50	3
50 - 60	3
60 - 70	1
70 - 80	0
80 - 90	1
Total	30

Histogram

b)

Classes	Class value	Frequency
20 - 30	25	15
30 - 40	35	7
40 - 50	45	3
50 - 60	55	3
60 - 70	65	1
70 - 80	75	0
80 - 90	85	1

c)

Classes	Class value	Frequency	Cummulative frequency
20 - 30	25	15	15
30 - 40	35	7	22
40 - 50	45	3	25
50 - 60	55	3	28
60 - 70	65	1	29
70 - 80	75	0	29
80 - 90	85	1	30

d) stem plot

Stem-and-leaf of X   N = 30

15	2	012234455566889
15	3	0013449
8	4	236
5	5	123
2	6	0
1	7
1	8	0

Leaf Unit = 1

e)

Statistics

Variable	Minimum	Q1	Median	Q3	Maximum	IQR
X	20.00	24.75	29.50	42.25	80.00	17.50