Chapter 14 Class 9 Statistics
Last updated at April 16, 2024 by Teachoo
Example 3 A teacher wanted to analyze the performance of two sections of students in a mathematics test of 100 marks. Looking at their performances, she found that a few students got under 20 marks and a few got 70 marks or above. So she decided to group them into intervals of varying sizes as follows: 0 - 20, 20 - 30, . . ., 60 - 70, 70 - 100. Then she formed the following table: Make histogram of the data The data has class intervals of varying width. So, we calculate adjusted frequency Adjusted frequency = (πΉππππ’ππππ¦ Γ π πππ’ππππ π ππ§π ππ πππ‘πππ£ππ)/(πΆπ’πππππ‘ π ππ§π ππ πππ‘πππ£ππ)