Question

It is fairly common for people to put on weight when they quit smoking. While a small weight gain is normal, excessive weight gain can create new health concerns that erode the benefits of not smoking. The accompanying table shows a portion of the weight data for 50 women before quitting and six months after quitting.

BeforeQuit	AfterQuit
140	155
144	142
138	153
145	146
118	129
150	149
119	136
125	127
131	158
126	139
124	127
131	141
140	139
140	140
130	136
123	143
132	145
124	126
144	165
117	136
148	163
137	140
133	147
133	142
123	123
134	137
130	140
123	124
125	129
133	136
136	147
127	131
122	134
128	129
133	143
138	150
127	136
126	134
131	140
126	118
130	132
146	146
141	135
125	126
160	163
151	154
135	149
110	105
123	128
135	147

Let the difference be defined as After Quitting – Before Quitting.

a. Construct and interpret the 95% confidence interval for the mean gain in weight. (Round your answers to 2 decimal places.)

b. Use the confidence interval to determine if the mean gain in weight differs from 5 pounds.

Answer 1