Homework SourseThe following is a frequency distribution of grades for a st
The following is a frequency distribution of grades for a statistics examination. Treat data as sample, compute sample mean..
Examination Grade
Frequency
40 49
2
50 59
4
60 69
10
70 79
25
80 89
14
90 99
5
| Examination Grade | Frequency |
| 40 49 | 2 |
| 50 59 | 4 |
| 60 69 | 10 |
| 70 79 | 25 |
| 80 89 | 14 |
| 90 99 | 5 |
Solution
As the intervals are given for data, let us calculate mid point as x value for each interval
Sample mean = 91.8367
| Examination Grade | Midpoint X | Frequency f | x*f | |
| 40 49 | 45 | 2 | 90.00 | |
| 50 59 | 55 | 4 | 220.00 | |
| 60 69 | 65 | 10 | 650.00 | |
| 70 79 | 75 | 25 | 1875.00 | |
| 80 89 | 85 | 14 | 1190.00 | |
| 90 99 | 95 | 5 | 475.00 | |
| 49 | 4500.00 | |||
| Mean | 4500/49 | 91.8367347 |
