Mean of Grouped Frequency Distribution by Assumed Mean Method

Q. Calculate the mean of the following distribution using step - deviation method.

$\begin{array}{cc}\text{Class Interval}& \text{Frequency}\\ 30-40& 10\\ 40-50& 6\\ 50-60& 8\\ 60-70& 12\\ 70-80& 5\\ 80-90& 9\end{array}$

1. 59.6
2. 58.6
3. 60
4. 54

Q. Given below is the concentration of SO₂ in air(in ppm = parts per million) in 30 localities:
$\begin{array}{cc}S{O}_2\text{concentration (in ppm)}& \text{Number of localities}\\ 0.00-0.04& 4\\ 0.04-0.08& 9\\ 0.08-0.12& 9\\ 0.12-0.16& 2\\ 0.16-0.20& 4\\ 0.20-0.24& 2\end{array}$
Find the mean of $S{O}_2$ concentration using assumed - mean method.

1. 0.096
2. 0.1
3. 0.122
4. 0.098

Q. Three friend A, B and C have 8, 10 and 12 chocolates respectively. Then has the chocolates which is equal to the average number of chocolates.

1. A
2. B
3. C

Q.

A class teacher has the following absentee record of 40 students of a class for the whole term. Find the mean number of days a student was absent.

$\begin{array}{cccccccc}\text{Number of days}& 0-6& 6-10& 10-14& 14-20& 20-28& 28-38& 38-40\\ \text{Number of students}& 11& 10& 7& 4& 4& 3& 1\end{array}$
$\left[3\right]$

Q.

Given below is the concentration of SO₂ in air (in ppm = parts per million) in 30 localities:
$\begin{array}{cc}S{O}_2\text{concentration (in ppm)}& \text{Number of localities}\\ 0.00-0.04& 4\\ 0.04-0.08& 9\\ 0.08-0.12& 9\\ 0.12-0.16& 2\\ 0.16-0.20& 4\\ 0.20-0.24& 2\end{array}$
Find the mean of $S{O}_2$ concentration using assumed - mean method.

1. 0.1

2. 0.099

3. 0.144

4. 0.16

Q. Given below is the concentration of SO₂ in air(in ppm = parts per million) in 30 localities:
$\begin{array}{cc}S{O}_2\text{concentration (in ppm)}& \text{Number of localities}\\ 0.00-0.04& 4\\ 0.04-0.08& 9\\ 0.08-0.12& 9\\ 0.12-0.16& 2\\ 0.16-0.20& 4\\ 0.20-0.24& 2\end{array}$
Find the mean of $S{O}_2$ concentration using assumed - mean method.

1. 0.1
2. 0.098
3. 0.122
4. 0.096

Q. The number of goals scored by Lionel Messi in the La Liga for 6 seasons from 2011-17 are tabulated below. Find the mean number of goals scored per season using the assumed mean method.

$\begin{array}{cc}Season& Number\\ & ofgoals\\ 2011-12& 50\\ 2012-13& 46\\ 2013-14& 28\\ 2014-15& 43\\ 2015-16& 26\\ 2016-17& 37\end{array}$

1. 35.4
2. 38.3
3. 39.5
4. 41

Q.

Calculate the Mean of the given distribution, using Assumed mean Method.

$\begin{array}{cc}\text{Marks}& \text{No. of Students}\\ 10-20& 2\\ 20-30& 6\\ 30-40& 10\\ 40-50& 12\\ 50-60& 9\\ 60-70& 8\\ 70-80& 4\\ 80-90& 3\end{array}$

1. 48.89

Q. For a given data set, the mean of the deviations is $\frac{120}{140}$ and the assumed mean is 25. Find the mean.

1. 0.03
2. 24.14
3. 25.86
4. 29.17