ABSTRACT
For confidence coefficient 0.95, 0.05 and /2 0.05/2 0.025.α = α = = From Table 5, Appendix
B, z 1.96.0.025 = The 95% confidence interval is:
p z p p qn ˆ ˆ 1.96 ˆ ˆ 0.5 1.96 0.5(0.5)60p3 /2 ˆ 3
3 3 3± σ ⇒ ± ⇒ ±α
0.5 0.127 (0.373,0.627)⇒ ± ⇒ We are 95% confident that the true proportion of patients who admit to both
habits is between 0.373 and 0.627. d. Let p4 = proportion of patients who admit to neither habit.
