3 Ex-3: Measures of Dispersion

  1. The following value represent district wise yield value of black pepper in Kerala. Find Range and Quartile deviation

300,350,550,420,340,655,250,360,250,315,200,138,275,120

  1. Find the mean deviation about mean for the following data
Class.interval Frequency
13-17 2
17-21 22
21-25 19
25-29 14
29-33 3
33-37 4
37-41 6
41-45 1
45-49 1
  1. Compute standard deviation and variance for the following data
Class.interval Frequency
2.5-3.5 4
3.5-4.5 6
4.5-5.5 10
5.5-6.5 26
6.5-7.5 24
7.5-8.5 15
8.5-9.5 10
9.5-10.5 5
  1. The following table shows average distribution of wage of 200 workers in a factory. Compute quartile deviation for the data
    wages No..of.workers
    0-40 30
    40-80 25
    80-120 30
    120-160 45
    160-200 25
    200-240 13
    240-280 24
    280-320 8
  2. The following are the data on number of insects caught during different days by two different types of traps. Determine which trap show more variation with respect to the number of insects caught
Trap1 Trap2
41 52
34 57
33 62
36 55
40 64
25 57
31 56
37 55
34 NA
30 NA
38 NA
  1. The following value represents the yield obtained from 15 mango trees. Find the quartile deviation, mean deviation and standard deviation.

105,102,91,86,150,96,70,175,110,101,99,66,120,135,79