NCERT Solutions
Class 11 - Mathematics - Chapter 13: STATISTICS
EXERCISE 13.1

Question. 1

Find the mean deviation about the mean for the data:

4, 7, 8, 9, 10, 12, 13, 17

Answer:

3

Question. 2

Find the mean deviation about the mean for the data:

38, 70, 48, 40, 42, 55, 63, 46, 54, 44

Answer:

8.4

Question. 3

Find the mean deviation about the median for the data:

13, 17, 16, 14, 11, 13, 10, 16, 11, 18, 12, 17

Answer:

2.33

Question. 4

Find the mean deviation about the median for the data:

36, 72, 46, 42, 60, 45, 53, 46, 51, 49

Answer:

7

Question. 5

Find the mean deviation about the mean for the following data:

\(x_i\): 5, 10, 15, 20, 25

\(f_i\): 7, 4, 6, 3, 5

Answer:

6.32

Question. 6

Find the mean deviation about the mean for the following data:

\(x_i\): 10, 30, 50, 70, 90

\(f_i\): 4, 24, 28, 16, 8

Answer:

16

Question. 7

Find the mean deviation about the median for the following data:

\(x_i\): 5, 7, 9, 10, 12, 15

\(f_i\): 8, 6, 2, 2, 2, 6

Answer:

3.23

Question. 8

Find the mean deviation about the median for the following data:

\(x_i\): 15, 21, 27, 30, 35

\(f_i\): 3, 5, 6, 7, 8

Answer:

5.1

Question. 9

Find the mean deviation about the mean for the grouped data:

Income per day (₹): 0–100, 100–200, 200–300, 300–400, 400–500, 500–600, 600–700, 700–800

No. of persons: 4, 8, 9, 10, 7, 5, 4, 3

Answer:

157.92

Question. 10

Find the mean deviation about the mean for the grouped data:

Height (cm): 95–105, 105–115, 115–125, 125–135, 135–145, 145–155

No. of boys: 9, 13, 26, 30, 12, 10

Answer:

11.28

Question. 11

Find the mean deviation about the median for the following data:

Marks: 0–10, 10–20, 20–30, 30–40, 40–50, 50–60

No. of girls: 6, 8, 14, 16, 4, 2

Answer:

10.34

Question. 12

Calculate the mean deviation about median age for the age distribution of 100 persons:

Age (years): 16–20, 21–25, 26–30, 31–35, 36–40, 41–45, 46–50, 51–55

No. of persons: 5, 6, 12, 14, 26, 12, 16, 9

Answer:

7.35

NCERT Solutions Class 11 – Mathematics – Chapter 13: STATISTICS – EXERCISE 13.1 | Detailed Answers