# CBSE Class 9 Maths Extra Questions: Chapter 14 - Statistics (with Answers)

Get here extra questions (with answers) for CBSE Class 9 Maths Chapter 14 - Statistics. These questions are quite helpful to brush up all important concepts and thus make preparations for the exam in a better way. Therefore, students must try to solve each question in order to increase their chances of scoring high in the CBSE Class 9 Maths Exam 2020-21.

**CBSE Class 9 Maths Extra Questions for Chapter 14 - Statistics****:**

**1. What do you mean by primary and secondary data?**

**Answer:**

Primary data means the information was collected by an investigator herself or himself with a definite objective in her or his mind. It is also named as the 'first-hand information'.

Secondary data is the information gathered from a source which already had the information stored. It is also termed as ‘second-hand information’.

**2. Find the range of the data given below that represents the marks obtained by students of a class.**

**55 36 95 73 60 42 25 78 75 62**

**Answer:**

Range = 70

Hint: The difference of the highest and the lowest values in the data is called the range of the data.

**3. What is the mean value of a set of observations?**

**Answer:**

The mean (or average) of a number of observations is the sum of the values of all the observations divided by the total number of observations.

**4. How do we calculate the median of given data?**

**Answer:**

The median is the middle number in a data set when the numbers are listed in either ascending or descending order. It can be calculated as follows:

**5. What is the mode of a given set of data?**

**Answer:**

The mode is that value of the observation which occurs most frequently, i.e., an observation with the maximum frequency is called the mode.

**Also Check: **

**NCERT Solutions for Class 9 Maths**

**6. The mean of 6 observations is 20. On removing one number from the given set, the mean of the remaining numbers becomes 16. Find the value of the removed number?**

**Answer:**

The value of the removed number = 40

**7. The mean of a given set of observations is 30. If each observation is increased by 3, find the mean of the new observations.**

**Answer:**

The mean of the new observations = 90

Hint: On increasing each number by x, the mean of the new numbers becomes x times.

**8. The mean of 21 observations is 32. If the mean of first 11 and last 11 observations is 23 and 28, then find the 11th observation.**

**Answer:**

The 11th observation = 111

Hint: (21 × 32) = [(11 × 23) + (11 × 28)] − 11th number

**9. Find the median of the following numbers:**

**3, 4, 5, 6, 9, 8, 8, 11, 4**

**Answer:**

Median of given numbers = 6

Hint: The number of terms is odd so the median will be the middle term.

**10. Find the mode of the following numbers:**

**9, 4, 17, 23, 4, 9, 11, 4, 17, 4, 23, 17, 7, 4, 11 **

**Answer: **

Mode of given numbers = 4

**Extra Questions for CBSE Class 9 Maths - All Chapters**

Students must go through the latest CBSE Syllabus for Class 9 Maths so that they can prepare according to the contents prescribed by the board.

**Also check:**

**CBSE Class 9 Maths Important Questions and Answers**

**CBSE Class 9 Maths Important MCQ (Chapter-wise)**