A study was instigated to see if southern California earthquakes of at least moder- ate size (having values of at least 4.4 on the Richter scale) are more likely to occur on certain days of the week than on others. The catalogs yielded the following data on 1,100 earthquakes.
| Day |
sun |
mon |
tues |
wed |
thurs |
fir |
sat |
| Number of earth quakes |
156 |
144 |
170 |
158 |
172 |
148 |
152 |
Test, at the 5 percent level, the hypothesis that an earthquake is equally likely to occur on any of the 7 days of the week.