(i)
It is given that the number of wage earners in firm A and firm B are 586 and 648 respectively, and the mean of monthly wages in firm A and firm B is Rs. 5253 each.
Since monthly wages and number of wage earners in firm A are given, therefore the total amount paid is the product of number of wage earners and mean of monthly wages.
Similarly, since monthly wages and number of wage earners in firm B are given, therefore the total amount paid is the product of number of wage earners and mean of monthly wages.
Thus, firm B pays the larger amount as monthly wages because the number of wage earners in firm B is more than firm A.
(ii)
Since the mean of both the firms are the same, therefore the variability is calculated by greater standard deviation.
It is given that the variance of the distribution of wages in firm A is 100.i.e.
The formula to calculate the standard deviation is,
Substitute 100 for
Similarly, it is given that the variance of the distribution of wages in firm B is 121, i.e.,
Substitute 121 for
Thus, firm B has greater variability in the individual wages.