Question

Please I need answer fast​

Answer 1

To Find :

The mean.

Solution :

Analysis :

Here we have use the direct method to find the mean as mentioned in the question. For that we first have to find the class mark for every class intervals. Then we have to multiply the class mark with the respective frequency. After dividing the multiplied total by total frequency we will get the required mean.

Explanation :

First we have to draw the frequency table (attachment).

We know that the formula for direct method to find the mean is,

$\\ \boxed{\bf Mean=\dfrac{\sum f_iy_i}{\sum f_i}}$

where,

• fᵢyᵢ = 10550
• fᵢ = 50

Using the required formula and substituting the required values,

$\\ \Rightarrow\sf Mean=\dfrac{10550}{50}$

$\\ \Rightarrow\sf Mean=\cancel{\dfrac{10550}{50}}$

$\\ \therefore\boxed{\bf Mean=211.}$

The mean is 211.

Explore More :

Mean by Short-Cut Method :

$\bf Mean=a+\dfrac{\sum f_id_i}{\sum f_i}$

Mean by Step Deviation Method :

$\bf Mean=a+c\times\dfrac{\sum f_iu_i}{\sum f_i}$

where,

• dᵢ = Class Mark - Assumed Mean
• a = Assumed Mean
• c = Width of the Class
• uᵢ = Class Mark - Assumed Mean
• fᵢ = Frequency

Answer 2

$\: \: \: \: \: \: \: \: \: \:\large{\underline{\star{\sf{Frequency\: distribution\: table}}}}$

⠀

To find:

• Mean of the given data.

⠀

Solution:

⠀

➲ We have a data of daily expenditure on food of 50 households, and need to find the mean.

⠀

• First of all, we will make a frequency distribution table (attachment).

⠀

☆ Consider

⠀

1. No. of households = $\bf{f_i}$
2. Class marks = $\bf{x_i}$

⠀

※ In this question, we will use direct method to find the mean.

⠀

⠀⠀⠀⠀⠀⠀❏ Formula used

⠀

$\large{\boxed{\boxed{\sf{\overline{X} = \dfrac{\sum{f_i x_i}}{\sum{f_i}}}}}}$

⠀

Here,

• $\rm{\sum{f_i x_i} = 10550}$
• $\rm{\sum{f_i} = 50}$

⠀

Substituting the values

⠀

$\tt\longrightarrow{Mean = \dfrac{10550}{50}}$

⠀

$\tt\longrightarrow{Mean = 211}$

⠀

Hence,

• Mean of the given data is 211.

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