Mean

Q.

The AM of $9$ terms is $15$. If one more term is added to this series, then AM becomes $16$. The value of the added term is.

1. $30$

2. $27$

3. $25$

4. $23$

5. $20$

Q.

The mean weight of a class of 24 students is 48 kg. If the weight of the teacher be included, then the mean weight increases by 500 g. Find the weight of the teacher.

Q.

What is meant by the mean of a given set of observations?

1. The most frequently occuring value of the observation.

2. The average value of the given set of observations

3. The value of a given number of observations which divides it into exactly two parts.

4. All of these

Q. The following table shows the number of saplings planted by 30 students. Fill in the boxes and find the average number of saplings planted by each student.

No. of saplings (Scores) xi	No. of students (frequncy) fi	fi×xi
1	4	4
2	6	$\boxed{0}$
3	12	$\boxed{0}$
4	8	$\boxed{0}$
	N = $\boxed{0}$	∑fixi=$\boxed{0}$

Mean $\overline{x}$ = $\frac{\boxed{0}}{N}$

Q.

The marks obtained by 12 students in a mathematics examination are given below.

48, 78, 93, 90, 66, 54, 83, 58, 60, 75, 89, 84.

Find (i) the mean of the marks; (ii) the mean mark of the students if each student is given 4 grace marks.

Q.

What is the geometric mean of $32$ and $2$?

Q.

What is the geometric mean of $7$ and $63$?

Q. Using the aasumed - mean method, find the mean height of the plants from the following frequency-distribution table:

$\begin{array}{cccccc}Height\left(incm\right)x_i& 60& 64& 68& 72& 76\\ Numberofplants{f}_i& 5& 16& 40& 30& 9\end{array}$
[4 MARKS]

Q. If the mean of first y natural numbers is 28. Find the value of y

Q.

In the following table, the number of villains caught by BATMAN and SUPERMAN during a week is given. Whose daily average is more and how much is it?

1. BATMAN, 2

2. SUPERMAN, 2

3. BATMAN, 3

4. SUPERMAN, 3

Q. Find difference between mean and median. If the difference between mode and median of a data is 18, use the relation $Mode=3Median-2Mean$.

1. 5
2. 4
3. 6
4. 9

Q.

. The mean age of combined group of men and women is $35$ years. If the mean age of men is $36$ years and that of women is $32$ years. The percentage of men and women in the group is respectively given by:

1. Men = $75\%$, women = $25\%$

2. Men = $70\%$, women = $30\%$

3. Men = $50\%$, women = $50\%$

4. Men = $25\%$, women = $75\%$

Q. Factorize: $27p^3+8q^3$

1. $(3p+2q)[9p^2-6pq+4q^2]$
2. $(2p+3q)[9p^2-6pq+4q^2]$
3. $(3p+2q)[8p^2-4pq+4q^2]$
4. $(3p+2q)[6p^2-6pq+2q^2]$

Q.

The mean of the following distribution is:

$$\begin{array}{ccccc}{x}_i& 10& 13& 16& 19\\ f_i& 2& 5& 7& 6\end{array}$$

1. 15.35

2. 15.2

3. 16

4. 15.55

Q.

The mean of a number of observations is

1. The difference between any two observations
2. None of the above
3. The simple average of the observations
4. The sum of the observations

Q.

The mean of $x,2x,5x+1and3$ is

1. $2x$

2. $2x+1$

3. $5x+1$

4. $8x$

Q. The average age of Tom's 5 family members excluding Tom is 35. Tom is 5 years old, average age of his family including him is .

1. $30$ years
2. $25$ years
3. $15$ years

Q. If the mean of 100 observations is 50, then the sum of all the observations is ____.

1. 5105
2. 5260
3. 5000
4. 5050

Q. List five rational number between:

Q. Find the difference between the arithmetic means of all even and odd numbers between 60 and 70.
(2 marks)

Q.

Sara got 98, 100, 65, 78, 98, 35, 100, 100, 45 and 50 on her 10 consequitive reading tests each worthing 100 marks. What is the mean of her test scores?

1. 67.1

2. 30.5

3. 7.69

4. 76.9

Q. The numbers of toffees contained in each of the five jars are presented in the following table:

Jar 1	Jar 2	Jar 3	Jar 4	Jar 5
$10$	$30$	$50$	$25$	$40$

Thomas wants to equally distribute the toffees in five jars. After equal distribution, how many toffess each of the five jars will contain?

1. $155$
2. $31$
3. $775$
4. None of the above

Q. A consumer buys $100$ units of $Good-Y$ at $Rs.5$ per unit. The price elasticity of demand for the good is $2$. At what price will he be willing to buy $140$ units of $Good-Y$?

Q.

The number of members in the 40 families in a village is as follows: 1, 6, 5, 4, 3, 2, 7, 2, 3, 4, 5, 6, 4, 6, 2, 3, 2, 1, 4, 5, 6, 7, 3, 4, 5, 2, 4, 3, 2, 3, 5, 5, 4, 6, 2, 3, 5, 6, 4, 2. Prepare a frequency table and find the mean of members of 40 families.

Q. The mean of 5 numbers is 30. If one number is excluded, the mean is 28. The excluded number is:

1. 28
2. 30
3. 35
4. 38

Q.

The mean of the following distribution is:

$$\begin{array}{ccccc}{x}_i& 10& 13& 16& 19\\ f_i& 2& 5& 7& 6\end{array}$$

1. 15.2

2. 15.35

3. 15.55

4. 16

Q. If mean of the following data is 20.2. Find the value of p.

Q. Choose the correct options with respect to the mean of the data.

1. It is the most frequently occuring value in the data set.
2. It is the sum of all the data points divided by the total number of data points.
3. It lies between the smallest and the largest value of the data set.
4. The data set can have two values of mean.

Q. Nelly computed the mean of $5$ numbers to be $7$. When she checks her work, she realizes she misread $3$ as $8$. The actual mean of the data set is .

Q.

Virender Sehwag’s score card for a five match ODI series is 23, 89, 76, 54, 102 runs respectively. What is Sehwag’s mean score for the tournament?

1. 66.8

2. 67.8

3. 68.8

4. 65.8