Q2 of 40 Page 210

Number of families in a village in correspondence with the number of children are given below:


Find the mean number of children per family.

Given is the frequency distribution table for ungrouped data.

We have



⇒ 11 families each have no children,


25 families each have 1 child,


And so on…


This also implies that,


Total number of children of 11 families = 0 × 11 = 0,


Total number of children of 25 families = 1 × 25 = 25,


And so on…


Mean of such ungrouped data is given by



⇒


⇒ [∵ ∑xifi = 144 & ∑fi = 84]


⇒ Mean = 1.7143


Thus, mean number of children per family is 1.7143.


More from this chapter

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9

A company manufactures car batteries of a particular type. The life (in years) of 40 batteries were recorded as follows:

2.6 3.0 3.7 3.2 2.2 4.1 3.5 4.5


3.5 2.3 3.2 3.4 3.8 3.2 4.6 3.7


2.5 4.4 3.4 3.3 2.9 3.0 4.3 2.8


3.5 3.2 3.9 3.2 3.2 3.1 3.7 3.4


4.6 3.8 3.2 2.6 3.5 4.2 2.9 3.6


Construct a grouped frequency distribution table with exclusive classes for this data, using class intervals of size 0.5 starting from the interval 2 - 2.5.


 1

Weights of parcels in a transport office are given below.


Find the mean weight of the parcels.

 3

If the mean of the following frequency distribution is 7.2 find value of ‘K’.

 4

Number of villages with respect to their population as per India census 2011 are given below.


Find the average population in each village.