Direct Method

Q.

Find the mean of the distribution: Class $1-3,3-5,5-7,7-10$, Frequency $9,22,27,17$.

Q.

Question 9
Following table gives the distribution of students of sections A and B of a class according to the marks obtained by them.

$\begin{array}{cccc}\text{Section A}& & \text{Section B}& \\ \text{Marks}& \text{Frequency}& \text{Marks}& \text{Frequency}\\ 0-15& 5& 0-15& 3\\ 15-30& 12& 15-30& 16\\ 30-45& 28& 30-45& 25\\ 45-60& 30& 45-60& 27\\ 60-75& 35& 60-75& 40\\ 75-90& 13& 75-90& 10\end{array}$

Represent the marks of the students of both the sections on the same graph by two frequency polygons. What do you observe?

Q. The height of 7 students are listed.


The mean height of the students before and after increasing the height by 2 cm is

1. 162 cm, 164 cm
2. 166 cm, 170 cm
3. 161.67 cm, 171, 26 cm

Q.

If the numbers 3, 5, 7, 4 have frequencies x, x+4, x-3, x+8 with their arithmetic mean of 4, then x will be _____.

1. $\frac{5}{3}$

2. $\frac{7}{4}$

3. $\frac{2}{3}$

4. $\frac{11}{3}$

Q. Different types of toys are listed with their prices.The mean of the given data is 18. Find the value of x.

1. 20
2. 18
3. 12
4. 22

Q. The time spent by a person for various programs is given. If he wants to spend equal time in all programs, what fraction of the total time will he have to spend?

1. $\frac{8}{40}$
2. $\frac{11}{40}$
3. $\frac{4}{8}$
4. $\frac{10}{40}$

Q. If the mean of five observations $x,x+2,x+4,x+6andx+8$ is $11$, then the mean of first three observations is:

Q.

The base for given base method multiplication is:

___

Q. The test scores of Clara are 68, 86, 76, x, 90. Which of the following gives the value of x, if the mean is 80?

1. 70
2. 80
3. 82
4. 72

Q. The height of 7 students are listed.


The mean height of the students before and after increasing the height by 2 cm is

1. 166 cm, 170 cm
2. 161.67 cm, 171, 26 cm
3. 162 cm, 164 cm

Q. The number of kids and adults who participated in the outdoor games is given.


Which of the following is true about the mean of the two data?

1. Mean of both data are same.
2. Mean of data 1(kids) > Mean of data 2 (adults)
3. Mean of data 1(kids) < Mean of data 2 (adults)
4. Mean of data 1 is twice that of mean of data2.