NCERT Class 11 Statistics Organisation of Data

EXERCISES

1. Which of the following alternatives is true?

(i) The class midpoint is equal to:

(a) The average of the upper class limit and the lower class limit.

(b) The product of upper class limit and the lower class limit.

(c) The ratio of the upper class limit and the lower class limit.

(d) None of the above.

(ii) The frequency distribution of two variables is known as

(a) Univariate Distribution

(b) Bivariate Distribution

(c) Multivariate Distribution

(d) None of the above

(iii) Statistical calculations in classified data are based on

(a) the actual values of observations

(b) the upper class limits

(c) the lower class limits

(d) the class midpoints

(iv) Under Exclusive method,

(a) the upper class limit of a class is excluded in the class interval

(b) the upper class limit of a class is included in the class interval

(c) the lower class limit of a class is excluded in the class interval

(d) the lower class limit of a class is included in the class interval

(v) Range is the

(a) difference between the largest and the smallest observations

(b) difference between the smallest and the largest observations

(c) average of the largest and the smallest observations

(d) ratio of the largest to the smallest observation

2. Can there be any advantage in classifying things? Explain with an example from your daily life.

3. What is a variable? Distinguish between a discrete and a continuous variable.

4. Explain the ‘exclusive’ and ‘inclusive’ methods used in classification of data.

5. Use the data in Table 3.2 that relate to monthly household expenditure (in Rs) on food of 50 households and

(i) Obtain the range of monthly household expenditure on food.

(ii) Divide the range into appropriate number of class intervals and obtain the frequency distribution of expenditure.

(iii) Find the number of households whose monthly expenditure on food is

   (a) less than Rs 2000

   (b) more than Rs 3000

   (c) between Rs 1500 and Rs 2500

6. In a city 45 families were surveyed for the number of domestic appliances they used. Prepare a frequency array based on their replies as recorded below.

1 3 2 2 2 2 1 2 1 2 2 3 3 3 3

3 3 2 3 2 2 6 1 6 2 1 5 1 5 3

2 4 2 7 4 2 4 3 4 2 0 3 1 4 3

7. What is ‘loss of information’ in classified data?

8. Do you agree that classified data is better than raw data?

9. Distinguish between univariate and bivariate frequency distribution.

10. Prepare a frequency distribution by inclusive method taking class interval of 7 from the following data:

28 17 15 22 29 21 23 27 18 12 7 2 9 4 6

1 8 3 10 5 20 16 12 8 4 33 27 21 15 9

3 36 27 18 9 2 4 6 32 31 29 18 14 13

15 11 9 7 1 5 37 32 28 26 24 20 19 25

19 20

Please refer to attached file for NCERT Class 11 Statistics Organisation of Data