Question

collect 20 samples values of any variable and prepare a report for the following statistics: Frequency Histogram (5 bins, Intervals or class), Steam and Leaf Diagram, Dot Diagram. Identify the concentration and variation tendencies from the data charts.

Answer 1

Let's take 20 sample values with some frequencies as given in the following table:

	value	Freq
1	4	5
2	6	6
3	7	5
4	8	5
5	9	6
6	11	3
7	14	4
8	15	6
9	18	5
10	21	7
11	26	4
12	30	4
13	34	8
14	36	2
15	39	5
16	40	4
17	42	8
18	45	3
19	47	5
20	48	5

This sample values can be tabulated again according to 5 class intervals as:

	Intervals	Freq
1	[0,12)	30
2	[12,24)	22
3	[24,36)	16
4	[36,48)	27
5	[48,60)	5

Stem and Leaf plot for values:

The decimal point is 1 digit(s) to the right of the |

  0 | 44444
  0 | 6666667777788888999999
  1 | 1114444
  1 | 55555588888
  2 | 1111111
  2 | 6666
  3 | 000044444444
  3 | 6699999
  4 | 000022222222
  4 | 5557777788888

This sample points of values are quite scattered in the dot diagram. There are two modes in the data, those are 34 and 42.

Mean in this data is 24.7

Median is at 21.