| i | x (minutes) |
fi | pi | npi | (fi-npi) |  |
|---|---|---|---|---|---|---|
| 1 | 0-5 | 39 | 0.438 | 44.677 | -5.677 | 0.721 |
| 2 | 5-10 | 25 | 0.246 | 25.108 | -0.108 | 0.000 |
| 3 | 10-15 | 20 | 0.138 | 14.110 | 5.890 | 2.458 |
| 4 | 15-20 | 11 | 0.078 | 7.930 | 3.070 | 1.189 |
| 5 | 20 above | 7 | 0.100 | 10.175 | -3.175 | 0.990 |
| Total | 102 | 1.000 | 102.000 | 0.000 | 5.359 |
Note: i is each interval;
x is the arrival number per minute.