Although the phenomenon is not well understood, it appears that people born during the winter months are slightly more likely to develop schizophrenia than people born at other times (Bradbury & Miller, 1985). The following hypothetical data represent a sample of 50 individuals diagnosed with schizophrenia and a sample of 100 people with no psychotic diagnosis. Each individual is also classified according to season in which he or she was born. Do the data indicate a significant relationship between schizophrenia and the season of birth? Test at the .05 level of significance.
|
Season of Birth
|
|
Summer
|
Fall
|
Winter
|
Spring
|
|
No disorder
|
27
|
26
|
23
|
28
|
|
Schizophrenia
|
8
|
9
|
17
|
12
|