The heights of 50 students, measured to the nearest centimeters, have been found to be as follows:
i) Represent the data given above by a grouped frequency distribution table, taking the class intervals as 160-165, 165-170, etc.
ii) What can you conclude about their heights from the table?
161 | 150 | 154 | 165 | 168 | 161 | 154 | 162 | 150 | 151 |
162 | 164 | 171 | 165 | 158 | 154 | 156 | 172 | 160 | 170 |
153 | 159 | 161 | 170 | 162 | 165 | 166 | 168 | 165 | 164 |
154 | 152 | 153 | 156 | 158 | 162 | 160 | 161 | 173 | 166 |
161 | 159 | 162 | 167 | 168 | 159 | 158 | 153 | 154 | 159 |
Solution:
(i) A grouped frequency distribution table with a class size of 5 for the heights of 50 students can be constructed as follows.
HEIGHT (in cm) |
NO OF STUDENTS (frequency) |
150-155 155-160 160-165 165-170 170-175 |
12 9 14 10 5 |
TOTAL |
50 |
Since ‘150’ is the lowest value, we started the 1st class interval at 150.
(ii) The following conclusions can be drawn from the table:
- 70% of the students (35 students) are below 165 cm.
- Only 10% of the students (5 students) are of height of 170 cm or more.
Video Solution:
The heights of 50 students, measured to the nearest centimeters, have been found to be as follows: i) Represent the data given above by a grouped frequency distribution table, taking the class intervals as 160-165, 165-170, etc. ii) What can you conclude about their heights from the table?
NCERT Solutions for Class 9 Maths - Chapter 14 Exercise 14.2 Question 4:
Summary:
The heights of 50 students, measured to the nearest centimeters, have been given. The grouped frequency distribution table, taking the class intervals as 160-165, 165-170, etc. has been constructed and the following conclusions can be drawn from the table: 70% of the students (35 students) are below 165 cm, only 10% of the students (5 students) are of height of 170 cm or more.