The runs scored by two batsmen in 10 innings are: A: 65, 58, 68, 44, 48, 45, 60, 62, 60, 50
B: 48, 80, 58, 44, 52.65, 73, 56, 64.50.
Which of the batsmen is more consistent and which one is more variable?
The marks obtained (out of 100) by two students in 10 qualifying tests were: A: 48, 53, 58, 41, 54, 52, 54, 49, 51, 50
B: 11, 98, 60, 94, 48, 52,17, 90, 20, 20
Who is more consistent in performance and who is more variable?
The mean and standard deviation of marks obtained by 50 students of a class in three subjects, Mathematics, Physics and Chemistry are given below:
Subject        Mathematics         Physics         Chemistry
Mean            42                32             40.9
StandardÂ
deviation         12                 15              20
which of the three subjects shows the highest variability in marks and which shows the lowest?
The means are all different.
∴ we will compare co-efficients of variations.
Mathematics:
        Mean, Â
         Â
                                           ...(i)
Physics:
       Mean,  Â
                 Â
                                      ...(ii)
Chemistry
      Mean, Â
                Â
                                         ...(iii)
From (i), (ii) and (iii), we conclude that Chemistry with highest C.V. = 48.9% shows the highest variability and Mathematics with C.V. = 28.6% shows the lowest variability.
An analysis of monthly wages paid to workers in two firms A and B, belonging to the same industry, gives the following results:
                                          Firm A             Firm B
No. of wage earners                             586               648
Mean of monthly wages                         Rs 5253           Rs 5253
Variance of the distribution of wages                  100               121
(i) Which firm A or B pays larger amount as monthly wages?
(ii) Which firm A or B shows greater variability in individual wages?