Question

The following table shows the frequency distribution of the ages of 35 people. Find the mean of the data.
(( in class interval column last is 40 - 50 ))​

Answer 1

Given :

• Frequency distribution of the ages of 35 people .

To Find :

• Mean of the data .

Solution :

Refer to the attachment

Using Formula :

$\longmapsto\tt\boxed{Mean=\dfrac{\sum{f}_{i}{x}_{i}}{fi}}$

Putting Values :

$\longmapsto\tt{\cancel\dfrac{705}{35}}$

$\longmapsto\tt\bf{20.1}$

So , The Mean of the data is 20.1 .

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Mean :

It is the sum of values of all the observations divided by the total no. of observations .

Mode :

The observation that occurs for the maximum time is called Mode of the Data .

Median :

The central value that occurs in the centre when we arrange the data in ascending order .

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Answer 2

Given :-

A frequecy table

To Find :-

Mean

Solution :-

$\boxed{\begin{array}{clclc} \bf CI&\bf f_i & \bf x_i & \bf f_ix_i \\0-10&5&5&5(5) = 25\\10-20&15&15&15(15) = 225\\20-30&10&25&10(25)=250\\ 30-40&2&35&2(35) = 70\\ 40-50&3&45&3(45) = 135 \\ &35&&&705\end{array}}$

Now

$\bf Mean = \dfrac{\sum f_ix_i}{\sum fi}$

$\sf Mean = \dfrac{705}{35}$

$\sf Mean = \dfrac{141}{7}$

$\sf Mean = 20.1$

Therefore, Option C is correct