The marks obtained by 50 students in a test are tabulated below : | Marks : | 0 - 15 | 15 - 30 | 30 - 45 | 45 - 60 | 60 - 75 | |---|---|---|---|---|---| | Number of students : | 3 | 9 | 20 | 15 | 3 | The number of students who got less than 45 marks is :

Step 1: Identify relevant classes

To find the number of students who scored less than 45 marks, we need to consider all the classes where the upper limit is less than or equal to 45. These classes are 0-15, 15-30, and 30-45.

Step 2: Sum the frequencies

Now, we sum the number of students (frequencies) corresponding to each of these identified classes. For the 0-15 class, there are 3 students. For the 15-30 class, there are 9 students. For the 30-45 class, there are 20 students.

Step 3: Calculate the total

Adding these frequencies together, $3 + 9 + 20$, gives us the total number of students who scored less than 45 marks.

More from this chapter

• **Example 6.** Find mean of the following data. | Class | 0-15 | 15-30 | 30-45 | 45-60 | 60-75 | 75-90 | |:---: |:---: |:---: |:---: |:---: |:---: |:---: | | **
• Example 2. The mean of the following data is 14. Find the value of k. |c|c|c|c|c|c| x & 5 & 10 & 15 & 20 & 25 f & 7 & k & 8 & 4 & 5
• Find the mean of the following frequency distribution: class intervals 0-10, 10-20, 20-30, 30-40, 40-50 with frequencies 5, 8, 15, 16, 6.
• Find the mean of 4, 8, 15, 16, 23, 42
• A survey regarding the heights (in cm) of 50 girls of class X of a school was conducted and the following data was obtained: | Height (in cm) | Number of girls
• In the following table, the median age of 200 spectators of a football match is 32. Find the missing frequencies p and q. | Age (in years) | Number of Spectator
• The government rescued 100 people after a train accident. Their ages were recorded in the following table. Find their mean age. | Age (in years) | Number of peo
• Using empirical relationship, the mode of a distribution whose mean is 7.2 and the median 7.1, is:

All Statistics solutions →