The figures below show to t he nearest minute 80 students waited to be served in a canteen.
Waiting time No. of students .Freq
1-5 4 4
6-10 7 11
11-15 11 22
16-20 18 ?
21-25 22 ?
26-30 10 ?
31-35 5 ?
36-40 3 ?
How do i find cumulative frequency??? Don't want all the answer just need to know how to find for one, and i will try to find the rest from there
look at the last two columns
first row: no. of students =4, so current sum=4
second row: no. of students = 7, sum of students = what it was in the last row + number of students
= 4+7 = 11
third row: no. of students = 11
sum = 11+11=22
fourth row: (your first ?)
no. of students = 18
new sum = 22+18 = 40
Can you follow my steps?
now continue down for the rest of the chart.
Don't make any arithmetic errors, once you mess up, all answers after that will be wrong.
this is the most awefull explenation of cumulative frequence...... ever!!!!!!!
27278
To find the cumulative frequency, you need to add up the frequency of each interval and all the intervals before it.
In this case, for the cumulative frequency of the 16-20 minute waiting time interval, you add the frequency of that interval with the cumulative frequency of the previous interval(s).
Here's how you can calculate it:
1. Start with the first interval:
- The cumulative frequency of the 1-5 minute waiting time interval is equal to the frequency of that interval, which is 4.
2. Move to the second interval:
- The cumulative frequency of the 6-10 minute waiting time interval is equal to the frequency of that interval, which is 7, plus the cumulative frequency of the previous interval, which is 4. So, it becomes 7 + 4 = 11.
3. Repeat the same process for the remaining intervals:
- To find the cumulative frequency of the 11-15 minute waiting time interval, add the frequency of that interval (11) to the cumulative frequency of the previous interval, which is 11. So, it becomes 11 + 11 = 22.
- To find the cumulative frequency of the 16-20 minute waiting time interval, add the frequency of that interval (18) to the cumulative frequency of the previous interval, which is 22. So, it becomes 18 + 22 = 40.
- Continue this process for the remaining intervals.
By applying this process, you can find the cumulative frequency for each interval in the table.