Section 7.2

Question 9

In a test of the effectiveness of garlic for lowering cholesterol, 44 subjects were treated with garlic in a processed tablet form. Cholesterol levels were measured before and after the treatment. The changes (beforeafter) in their levels of LDL cholesterol (in mg/dL) have a mean of 5.6 and a standard deviation of 19.4. Construct a 95% confidence interval estimate of the mean net change in LDL cholesterol after the garlic treatment. What does the confidence interval suggest about the effectiveness of garlic in reducing LDL cholesterol?

View a t distribution table.

Restaurant Drive-Through Service Times X Service Times (seconds) Restaurant X Restaurant Y 82 122 118 145 262 100 124 158 114 173 181 119 149 164 212 138 107 128 126 125 332 311 181 116 154 135 133 222 214 297 144 94 237 244 189 132 95 132 239 145 158 198 168 123 60 144 198 151 140 135 205 176 115 143 178 148 162 132 174 134 186 197 236 189 351 240 231 250 239 235 309 214 195 180 183 167 82 101 57 176 105 147 178 158 176 79 149 146 98 127 154 161 126 135 307 144 129 181 149 131 Print DoneNEGATIVE z Scores Standard Normal (z) Distribution: Cumulative Area from the LEFT -3.50 and -3.4 -14 07004 -33 9005 0006 -11 -32 -31 -10 0014 -20 -21 -27 -26 -25 -14 -23 -12 -21 -20 -19 -14 -15 -13 7151 -LI -1.1 -10 2050 2713 3121 -04 3409 -03 -02\fNEGATIVE z Scores Standard Normal (z) Distribution: Cumulative Area from the LEFT 01 04 -3.50 and -350 and LOWIT -34 10303 10003 8003 000] -13 DO04 -32 -12 toor -1.1 -3.1 DOOR -10 0013 4012 -10 -2.9 -20 10019 CONT 0016 0021 -21 0026 0025 0073 8022 -28 0027 -27 -27 DOAT 6041 DO39 10051 -25 4073 -24 -23 -23 0136 0154 -21 10170 -20 07-44 OFT4 0344 -17 0435 -1. 0645 DAST -15 OTH -15 -IA 0749 -13 1020 -1083 -13 1131 1113 1086 1038 11 79 -1.1 1321 1231 1230 1218 1357 1314 1-401 1379 -1.0 -1.1 1562 -01 -10 1841 1932 -DB 3119 2451 2743 2010 -05 3050 5015 -0.4 9300 3520 3821 4013 -03 AGOT 4443 4364 4747 4483 4404 -0.1 4840 -00POSITIVE z Scores Cumulative Area from the LEFT 06 5218 8319 5358 5000 5040 5120 5714 5753 5396 5438 SITE 5517 0.1 6103 6141 5790 5832 5910 0.2 6517 03 5443 0.3 6179 6217 6808 6844 04 6554 6501 6700 7123 7157 7190 .724 0.5 0.5 6015 6450 7019 7517 7549 1257 729 7357 7523 -7853 07 7580 7611 7642 7673 8106 8133 7861 7910 8340 8389 8159 8712 8577 8699 1.0 6438 8461 4830 1.1 9015 12 6845 9162 9177 1.3 9049 4306 9319 1.4 .9429 1.8 9332 9525 9645 1.6 9452 9463 9474 9625 9654 9564 9641 9761 9767 9713 9812 20 9857 9821 2.2 9911 9913 24 9600 2:5 26 9063 27 27 2.8 9906 2090 30 30 9095 12 150 and up 3150 wrid up