Question

Open the Body Data file under “Elementary Statistics, 13th edition” in Statdisk. This file contains information on the measurements of a sample of 300 individuals. The population mean systolic blood pressure is 124.7 with a variance of 211.10. The population standard deviation is said to be roughly 14.5. For this exercise, refer to pages 7, 11, and 12 of the Statdisk User Manual document. Be sure to enter the population standard deviation in the appropriate box. Given that the systolic blood pressure is normally distributed, calculate the descriptive statistics for this column of data and paste it here.

100
112
134
126
114
134
118
138
114
124
138
110
116
134
100
92
124
100
106
158
132
116
122
132
138
128
134
112
122
134
106
104
158
94
144
128
120
112
100
116
162
110
122
130
130
112
154
92
108
128
124
108
132
120
120
126
128
106
110
146
128
156
114
96
122
120
136
106
124
114
136
108
136
112
120
136
112
122
120
142
120
110
108
142
112
160
102
118
130
98
140
108
120
106
126
120
128
114
128
128
138
116
112
114
120
186
138
118
168
116
142
126
138
140
136
114
114
118
134
100
154
130
132
122
120
104
120
140
88
132
122
126
108
126
104
130
110
160
106
134
124
112
142
116
120
132
132
142
122
134
102
108
122
120
134
158
122
108
120
112
118
126
120
142
118
128
158
96
156
122
116
136
126
120
130
124
94
126
146
112
102
122
112
134
136
112
110
106
126
130
118
132
126
116
114
114
114
136
124
154
116
112
126
136
144
124
150
110
100
142
146
98
128
128
156
122
118
124
112
122
128
158
114
112
134
106
136
94
118
146
106
106
120
106
118
144
130
120
116
106
122
112
150
122
122
114
102
166
134
126
126
118
116
106
110
112
114
126
102
120
122
114
130
112
126
130
130
116
160
144
118
138
120
108
114
106
140
120
142
120
108
114
112
112
102
108
142
106
104
134
106
164
136
100
130
96
132
132
104
104

Your calculations should include: Mean Median Mode Variance Standard Deviation Range I think that I calculated these correctly but would like to check.  

• Mean 122.96
• Median 121
• Mode 120
• Variance 251.276
• Standard Deviation 15.85169
• Range 98

Calculate a 90%, 95%, and 99% confidence interval and paste your results here.

As the level of confidence increases, what happens to the width of the confidence interval? Does it increase or decrease? Explain why this would happen.

Since the confidence interval relates to our willingness to calculate a confidence interval that does not include the population mean, what does this tell us about the width of the interval? Give an example of where you might use a 99% confidence interval and another where a 90% interval would be appropriate.

Based on the data in the “Measurement Data” file, you think that the mean systolic blood pressure is less than the national average of 124.7. Perform a hypothesis test at the 0.05 level of significance to verify this. Use the four-step process outlined in the file “Hypothesis Test for a Population Mean” in the classroom.

Answer 1