The mean of 5 numbers is 18. If one number is excluded, their mean is 16. Find the excluded number.

The mean of 200 items was 50. Later on, it was discovered that the two items were misread as 92 and 8 instead of 192 and 88. Find the correct mean.

The following data on the number of girls (to the nearest ten) per thousand boys in different sections of Indian society is given below:

(i) Represent the information above by a bar graph.

(ii) In the classroom discuss what conclusions can be arrived at from the graph.

Given below are the seats won by different political parties in the polling outcome of state assembly elections:

(i) Draw a bar graph to represent the polling results.

(ii) Which political party won the maximum number of seats?

The following table gives the lifetimes of 400 neon lamps:

(i) Represent the given information with the help of a histogram.

(ii) How many lamps have a lifetime of more than 700 hours?