calculating the frequency of a statistical series
After a test, the marks of 18 students have been grouped in the table below :
1. What is the number of students having obtained a mark between 12 and 16 (excluding 16).
2. How many students got less than 12?
| grade n | `0<=n<4` | `4<=n<8` | `8<=n<12` | `12<=n<16` | `16<=n<=20` |
|---|---|---|---|---|---|
| Number of students | 5 | 1 | 5 | ? | 6 |
1. What is the number of students having obtained a mark between 12 and 16 (excluding 16).
2. How many students got less than 12?
Course reminder : Statistics