The following table gives the number of children of 150 families in a village No. of children `(x)` : 0 1 2 3 4 5 No. of families `(f)` : 10 21 55 42 15 7 Find the average number of children per family.

The following distribution gives the number of accidents met by 160 workers in a factory during a month. No. of accidents (x) : 0 1 2 3 4 No. of workers (f) : 70 52 34 3 1 Find the average number of accidents per worker.

The following table gives the number of branches and number of plants in the garden of a school. No. of branches (x) : 2 3 4 5 6 No. of plants (f) : 49 43 57 38 13 Calculate the average number of branches per plant.

The numbers of children in 10 families of a locality are: 2, 4, 3, 4, 2, 3, 5, 1, 1, 5. Find the mean number of children per family.

In the first proof reading of a book containing 300 pages the following distribution of misprints was obtained: No. of misprints per page (x) : 0 1 2 3 4 5 No. of pages (f) : 154 95 36 9 5 1 Find the average number of misprints per page.

The number of children in 10 families of a locality are 2,4,3,4,2,0,3,5,1,6. Find the mean number of children per family.

The number of students absent in a class were recorded every day for 120 days and the information is given in the following frequency table: No. of students absent (x) : 0 1 2 3 4 5 6 7 No. of days (f) : 1 4 10 50 34 15 4 2 Find the mean number of students absent per day.

The number of telephone calls received at an exchange per interval for 250 successive one-minute intervals are given in the following frequency table: No. of calls (x) : 9 1 2 3 4 5 6 No. of intervals (f) : 15 24 29 46 54 43 39 Compute the mean number of calls per interval.

Represent the following numbers on the number line: 2, 0, 3, 5, 7, 11, 15

The following table gives the distribution of income of 100 families in a village. Calculate the standard deviation: Income Rs. 0-1000 1000-2000 2000-3000 3000-4000 4000-5000 5000-6000 No. of Families 18 26 30 12 10 4

Two different families A and B are blessed with equal number of children. There are 3 tickets to be distributed amongst the children of these families so that no child gets more than one ticket. If the probability that all the tickets go to children of the family B is (1)/(12) then the number of children in each family is : (a) 3 (b) 5 (c) 4 (d) 6