Average(Mean)

Q.

The mean weight of a group of seven boys is 56 kg. The individual weights (in kg) of six of them are 52, 57, 55, 60, 59 and 55. Find the weight of the seventh boy.

1. 33 kg

2. 54 kg

3. 22 kg

4. 30 kg

Q. Marks obtained by 40 students in a short assessment are given below, where a and b are missing data. [4 MARKS]
$\begin{array}{cccccc}Marks& 5& 6& 7& 8& 9\\ Numberof& 6& a& 16& 13& b\\ Students& & & & & \end{array}$
If the mean of the distribution is 7.2, find a and b.

Q. The mean weight of students in a group of seven is 55 kg. If the individual weights of 6 students are 52, 58, 55, 53, 56 and 54; then the weight of the seventh student is:

1. 55 kg
2. 60 kg
3. 57 kg
4. 50 kg

Q.

To study the effect of temperature on yield in a chemical process, five batches were produced at each of three temperature levels.

The results follow.

Construct an analysis of variance table.

Use a $0.05$ level of significance to test whether the temperature level has an effect on the mean yield of the process.

Temperature

Temperature/ Batches	$50°C$	$60°C$	$70°C$
I	$34$	$30$	$23$
II	$24$	$31$	$28$
III	$36$	$34$	$28$
IV	$39$	$23$	$30$
V	$32$	$27$	$31$

Q.

If the mean of the following frequency distribution is 4.5, find the misssing frequency f.

$\begin{array}{ccccccccccc}\text{Variable}& 1& 2& 3& 4& 5& 6& 7& 8& 9& 10\\ \text{Frequency}& 5& 12& \text{f}& 13& 7& 9& 12& 3& 11& 4\end{array}$

1. 25
2. 50
3. 35
4. 60

Q.

A football league scores on an average 1.3 goals per match.

What is the total goals scored in 22 matches?

1. 26.6

2. 29.6

3. 28.6

4. 25.3

Q.

The following table shows the runs scored by different batsmen in a tournament :

$\begin{array}{cc}\text{Player}& \text{Runs scored}\\ Kohli& 455\\ MSD& 243\\ Rohit& 346\\ Shikhar& 308\\ Karthik& 176\end{array}$

What is the average number of runs scored?

1. 297.5

2. 305.6

3. 332.6

4. 320

Q.

Calculate the mean of the following data by all three methods, and compare the results.

$\begin{array}{cc}ClassInterval& Frequency\\ 110-110& 8\\ 110-120& 9\\ 120-130& 11\\ 130-140& 12\\ 140-150& 10\end{array}$ [4 MARKS]

Q.

The Mean weight of 60 Students in a class is 60 kgs. The Mean weight of boys is 70 kgs while that of girls is 55 kgs.

Find the number of boys and girls in the class respectively.

1. 24 and 36

2. 18 and 42

3. 25 and 35

4. 20 and 40

Q.

The Runs scored by M.S Dhoni in 8 innings are given as :

52 , 58 , 64 , 72 , 24 , 8 , x and 112.

If the Average of the 8 innings is 62 , what was his score in the 7th innings.

1. 116

2. 86

3. 106

4. 96

Q.

The weights of $10$ boys are measured (in kg) and the results are listed below:

$35,38,30,34,29,36,28,33,32,26$.

What is the mean weight of the boys ?

Q.

An insect moves along a circular path of radius 10 cm with a constant speed. If it takes 1 minute to move from a point on the path to the diametrically opposite point, then, the following quantities:
1. Distance covered
2. Speed
3. Displacement
4. Average velocity
will be respectively:

1. 0.314 cm
   0.314 cm/min
   1cm
   1 cm/min

2. 314 cm
   314 cm/min
   0.1 cm
   0.1 cm/min

3. 31.4 cm
   31.4 cm/min
   20 cm
   0.33 cm/s

4. 3.14 cm
   3.14 cm/min
   10 cm
   10 cm/min

Q.

The distance (in feet) jumped by an athlete in a long jump competition are given as :
6.45 , 7.01 , 6.78 , 6.82 , 6.64 , 6.5

What is the mean distance he jumped?

1. 6.9

2. 6.6

3. 6.7

4. 6.8

Q. Find the coefficient of range for the following data.
1, 4, 5, 5, 2, 7

1. 0.25
2. 0.5
3. 0.8
4. 0.75

Q.

The following table gives the literacy rate (in percentage) of 35 cities. Find the mean literacy rate by step deviation method.
$\begin{array}{cc}\text{Literacy rate (in \%)}& \text{No. of cities}\\ 44-55& 3\\ 55-65& 10\\ 65-75& 11\\ 75-85& 8\\ 85-95& 3\end{array}$

1. 66.44

2. 69.43

3. 67.39

4. 71.55

Q.

The marks obtained by the students of a class, in an exam which was out of 50 marks is given below :

$\begin{array}{cc}Marks& Numberofstudents\\ 5& 1\\ 7& 2\\ 11& 2\\ 16& 3\\ 21& 5\\ 24& 6\\ 28& 3\\ 32& 5\\ 34& 8\\ 39& 6\\ 43& 4\\ 45& 2\\ 49& 3\end{array}$

Find the mean for the ungrouped data.

1. 24

2. 28

3. 30.5

4. 29.94

Q.

The height in centimetres of $30$ students of class $6$ in a school are given below:$138,130,132,138,140,138,140,152,132,140,155,140,132,138,140,150,138,140,150,155,150,152,155,140,138,132,155,138,140,132$If $150cm$ is the standard height of the students of the class, how many are below this?

Q.

The monthly consumption of petrol is given city wise in the following table :

$\begin{array}{cc}\text{City}& \text{Monthly consumption(in Lakhs)}\\ NewDelhi& 30\\ Mumbai& 28\\ Chennai& 22\\ Bengaluru& 33\\ Kolkata& 32\\ Baroda& 23\end{array}$

Find the Mean(average) consumption.

1. 30.5 Lakhs

2. 28 Lakhs

3. 27 Lakhs

4. 29 Lakhs

Q.

The mean of first ten even natural numbers is

1. 30

2. 10

3. 100

4. 11

Q. If the correlation coefficient between $x$ and $y$ is $0.6$, covariance is $27$ and variance of $y$ is $25$, then what is the variance of $x$?

1. $81$
2. $9/5$
3. $81/25$
4. $9$

Q.

The scores of 11 cricket players in a match is given below:

121 , 14 , 11 , 9 , 1 , 14 , 101 , 81 , 51 , 7 , 14

Find the median and mode of the given data .

1. 82

2. 11

3. 71

4. 130

Q.

The mean of first 10 whole numbers is:

1. 4.5

2. 5.5

3. 6.5

4. 4.5

Q. Find the $AM$ using Assumed mean method for the following data shows distance covered by $30$ passengers to perform their jobs.

1. $29.33$
2. $30.33$
3. $27.33$
4. $28.33$

Q.

If the mean of 2 and 4 is a and mean of 11 and 13 is b, find the value of $\frac{b}{a}$.

1. 5

2. 4

3. 12

4. 13

Q.

The following table shows marks secured by 140 students in an examination:
$\begin{array}{cc}\text{Marks}& \text{Number of students}\\ 0-10& 20\\ 10-20& 24\\ 20-30& 40\\ 30-40& 36\\ 40-50& 20\end{array}$
Calculate mean marks by the step deviation method.

1. 20.4

2. 25

3. 25.86

4. 26.92

Q. The speed in $kmph$ of 4 bikers are 10, 15, 25, and 20. Then the average speed of the bikers is .

1. 17.5 $kmph$
2. 17 $kmph$
3. 16.5 $kmph$
4. 18 $kmph$

Q. Calculate the arithmetic mean by assumed mean method for the data given below.

Marks	$0-10$	$10-20$	$20-30$	$30-40$	$40-50$	$50-60$
No. of students	$5$	$10$	$25$	$30$	$20$	$10$

Q.

The Mean of the first 10 prime numbers is ___.

Q. The average of 201, 205, 209, 305 and 410 is .

1. 256
2. 265
3. 266

Q.

Find the mean of the following observations: 20, 30, 40 and 50

1. 35

2. 25

3. 30

4. 20