In: Statistics and Probability
The table below shows whether a random collection of people will respond to a survey or not, in different age groups. Test the claim that cooperation of a subject and the age of a subject are independent. χ2R = 15.086
| 
 Age  | 
 18-21  | 
 22-29  | 
 30-39  | 
 40-49  | 
 50-59  | 
 60 and over  | 
| 
 responded  | 
 73  | 
 255  | 
 245  | 
 136  | 
 138  | 
 202  | 
| 
 refused  | 
 11  | 
 20  | 
 33  | 
 16  | 
 27  | 
 49  | 
Critical Values: z0.005 = 2.575, z0.01 = 2.325, z0.025 = 1.96, z0.05 = 1.645
When d.f.=6: t0.005 = 3.707, t0.01 = 3.143, t0.025 = 2.447, t0.05 = 1.943
When d.f.=9: t0.005 = 3.250, t0.01 = 2.821, t0.025 = 2.262, t0.05 = 1.833
When d.f.=44: t0.005 = 2.690, t0.01 = 2.412, t0.025 = 2.014, t0.05 = 1.679
When d.f.=100: t0.005 = 2.625, t0.01 = 2.364, t0.025 = 1.984, t0.05 = 1.660