**CBSE Class 9 Maths – MCQ and Online Tests – Unit 14 – Statistics**

Every year CBSE schools conducts Annual Assessment exams for 6,7,8,9,11th standards. These exams are very competitive to all the students. So our website provides online tests for all the 6,7,8,9,11th standard’s subjects. These tests are also very effective and useful for those who preparing for any competitive exams like Olympiad etc. It can boost their preparation level and confidence level by attempting these chapter wise online tests.

These online tests are based on latest CBSE syllabus. While attempting these our students can identify the weak lessons and continuously practice those lessons for attaining high marks. It also helps to revise the NCERT textbooks thoroughly.** **

**CBSE Class 9 Maths – MCQ and Online Tests – Unit 14 – Statistics**

Question 1.

A grouped frequency distribution table with classes of equal sizes using 63-72 (72 included) as one of the class is constructed for the following data:

30, 32, 45, 54, 74, 78, 108, 112, 66, 76, 88, 40, 14, 20, 15, 35, 44, 66, 75, 84, 95, 96, 102, 110, 88, 74, 112, 14, 34, 44.

The number of classes in the distribution will be:

(a) 9

(b) 10

(c) 11

(d) 12

## Answer

Answer: (b) 10

Question 2.

Let m be the mid-point and 1 be the lower class limit of a class in a continuous frequency distribution. The upper class limit of the class is:

(a) 2m + l

(b) 2m – l

(c) m – l

(d) m – 2l

## Answer

Answer: (b) 2m – l

Question 3.

The class marks of a frequency distribution are given as follows:

15, 20, 25, …

The class corresponding to the class mark 15 is:

(a) 12.5 – 17.5

(b) 17.5 – 22.5

(c) 18.5 – 21.5

(d) 19.5 – 20.5

## Answer

Answer: (a) 12.5 – 17.5

Question 4.

In the class intervals 10-20, 20-30, the number 20 is included in:

(a) 10-20

(b) 20-30

(c) both the intervals

(d) none of these intervals

## Answer

Answer: (b) 20-30

Question 5.

A grouped frequency table with class intervals of equal sizes using 250-270 (270 not included in this interval) as one of the class interval is constructed for the following data:

268, 220, 368, 258, 242, 310, 272, 342, 310, 290, 300, 320, 319, 304,402, 318, 406, 292, 354, 278, 210, 240, 330, 316, 406, 215, 258, 236.

The frequency of the class 370-390 is:

(a) 0

(b) 1

(c) 3

(d) 5

## Answer

Answer: (a) 0

Question 6.

The class mark of the class 90-130 is:

(a) 90

(b) 105

(c) 115

(d) 110

## Answer

Answer: (d) 110

Question 7.

The range of the data:

25, 81, 20, 22, 16, 6, 17,15,12, 30, 32, 10, 91, 8, 11, 20 is

(a) 10

(b) 75

(c) 85

(d) 26

## Answer

Answer: (c) 85

Question 8.

Mode of the data

15, 14, 19, 20, 16, 15, 16, 14, 15, 18, 14, 19, 16, 17, 16 is

(a) 14

(b) 15

(c) 16

(d) 17

## Answer

Answer: (c) 16

Question 9.

The mean of 25 observations is 26. Out of these observations if the mean of first 13 observations is 22 and that of the last 13 observations is 30, the 13th observation is:

(a) 23

(b) 26

(c) 28

(d) 30

## Answer

Answer: (b) 26

Question 10.

If \(\bar { x } \) represents the mean of n observations x_{1}, x_{2}, …, x_{n}, then value of \(\sum_{i=1}^{n}\left(x_{i}-\bar{x}\right)\) is:

(a) -1

(b) 0

(c) 1

(d) n – 1

## Answer

Answer: (b) 0

Question 11.

If each observation of the data is increased by 5, then their mean

(a) remains the same

(b) becomes 5 times the original mean

(c) is decreased by 5

(d) is increased by 5

## Answer

Answer: (d) is increased by 5

Question 12.

Let \(\bar { x } \) be the mean of x_{1}, x_{2}, …, x_{n} and y the mean of y_{1}, y_{2}, …, y_{n}. If z is the mean of x_{1}, x_{2}, …. x_{n}, y_{1}, y_{2}, …, y_{n}, then z is equal to

(a) \(\bar {x}+\bar{y} \)

(b) \(\frac{\bar {x}+\bar{y}}{2}\)

(c) \(\frac{\bar {x}+\bar{y}}{n}\)

(d) \(\frac{\bar {x}+\bar{y}}{2n}\)

## Answer

Answer: (b) \(\frac{\bar {x}+\bar{y}}{2}\)

Question 13.

If \(\bar { x } \) is the mean of x_{1}, x_{2}, …, x_{n}, then for a ? 0, the mean of ax_{1}, ax_{2}, …, ax_{n}, \(\frac{x_1}{a}\), \(\frac{x_2}{a}\), …….., \(\frac{x_n}{a}\) is

## Answer

Answer: (b)

Question 14.

If \(\bar { x_1 } \), \(\bar { x_2 } \), \(\bar { x_3 } \), …….., \(\bar { x_n } \) are the means of n groups with n_{1}, n_{2}, ……. n_{n} number of observations respectively, then the mean x of all the groups taken together is given by:

## Answer

Answer: (c)

Question 15.

In a frequency distribution, the mid value of a class is 10 and the width of the class is 6. The upper limit of the class is:

(a) 6

(b) 7

(c) 10

(d) 13

## Answer

Answer: (d) 13

Question 16.

The width of each of five continuous classes in a frequency distribution is 5 and the lower class-limit of the lowest class is 10. The lower class-limit of the highest class is:

(a) 15

(b) 30

(c) 35

(d) 40

## Answer

Answer: (b) 30

Question 17.

The median of the data

78, 56, 22, 34, 45, 54, 39, 68, 54, 84 is

(a) 45

(b) 49.5

(c) 54

(d) 56

## Answer

Answer: (c) 54

Question 18.

For drawing a frequency polygon of a continous frequency distribution, we plot the points whose ordinates are the frequencies of the respective classes and abcissae are respectively:

(a) upper limits of the classes

(b) lower limits of the classes

(c) class marks of the classes

(d) upper limits of preceding classes

## Answer

Answer: (c) class marks of the classes

Question 19.

To draw a histogram to represent the following frequency distribution:

the adjusted frequency for the class 25-45 is:

(a) 6

(b) 5

(c) 3

(d) 2

## Answer

Answer: (d) 2

Question 20.

The mean of five numbers is 30. If one number is excluded, their mean becomes 28. the excluded number is:

(a) 28

(b) 30

(c) 35

(d) 38

## Answer

Answer: (d) 38

## 0 comments:

## Post a Comment