Sale of Mathematics and Hindi books in the years 1999, 2000, 2001 and 2002 are given below:

In which year was the difference in the sale of the two subjects books least?

The mean of 10 observations was calculated as 40. It was detected on rechecking that the value of 45 was wrongly copied as 15. Find the correct mean.

Number of children in six different classes are given below. Represent the data on a bar graph

(a) Find the average number of children in the classes.
(b) Find the ratio of student of Class VI to the students of Class VIII

Study the bar graph given below and answer the questions that follow:

(a) What information does the above bar graph represent?
(b) In which year was production the least?
(c) After which year was the maximum rise in the production?
(d) Find the average production of rice during the 5 years.
(e) Find difference of rice productions between the years 2006 and 20'08.

Study the double bar graph shown below and answer the questions that follow:

(a) What information is represented by the above double bar graph?
(b) In which month, sales of brand A decreased as compared to the previous month?
(c) What is the difference in sales of both the brands for the month of June?
(d) Find the average sales of brand 8 for the six months,
(e) List all months for which the sales of brand 8 was less than that of brand A.
(f) Find the ratio of sales of brand A as compared to brand 8 for the month of January.

Observe the following data:

(a) Draw a double bar graph choosing an appropriate scale. What do you infer from the bar graph?
(b) Which class has the maximum number of students?
(c) In which class, the difference of total students and number of students present is minimum?
(d) Find the ratio of number of students present to the total number of students of Class IX,
(e) What percent of students of Class VI were absent?

A survey of 150 girls showed that 63 like tea while 87 dislike it. Out of these girls,C?r1e girl is chosen at random. What is the~obability that the chosen girls (i) like tea? (ii) dislike tea?

The mean marks of seven students are 55. The marks of 6 students are 52, 54, 55, 53, 56 and 54. Find the marks of seventh student

The following table shows the weight of 12 Players:

Find the mode and mean weight.

The population of four major cities in India in a particular year is given below:

Construct a bar graph to represent the above data.