In problems involving contingency table, how to decide the null hypothesis? In an investigation into the effectiveness of car seat belts, 292 accident victims were classified according to the severity of their injuries and whether they were wearing a seat belt at the time of the accident. The results were as follows: Wearing a seat belt Not wearing a seat belt Death 3 47 Severe injury 78 32 Minor injury 103 29 Determine whether the severity of injuries sustained is dependent on whether the victims are wearing a seat belt. The table below shows the numbers of births during one month at a particular hospital classified according to whether a particular medical characteristic was or wasn’t present during childbirth. Determine whether the presence of this characteristic is dependent on the age of the mother. Age of mother 20 21-25 26-30 31-35 36+ Total Characteristic present 10 12 9 4 3 38 Characteristic absent 5 51 38 25 5 124 Total 15 63 47 29 8 162
Hi. I guess in contingency table, our Ho will always be tht there is no relation between row and column!
