p¼15
100
¼ 0 : 15
Its standard error is
SEðpÞ¼ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi
ð 0 : 15 Þð 1 0 : 15 Þ
100r¼ 0 : 036
Therefore, a 95% confidence interval for the New England states smoking rate
pis given by
0 : 15 Gð 1 : 96 Þð 0 : 036 Þ¼ð 0 : 079 ; 0 : 221 ÞFigure 5.7 m 0 not included at 95% confidence interval form.Figure 5.8 m 0 included in 95% confidence interval form.202 INTRODUCTION TO STATISTICAL TESTS OF SIGNIFICANCE