Question

The effectiveness of a blood-pressure drug is being investigated. An experimenter finds that, on average, the reduction in systolic blood pressure is 76.9 for a sample of size 498 and standard deviation 14.7. Estimate how much the drug will lower a typical patient's systolic blood pressure (using a 98% confidence level). Enter your answer as a tri-linear inequality accurate to one decimal place (because the sample statistics are reported accurate to one decimal place). <u Answer should be obtained without any preliminary rounding.

Answer 1

Solution : Given that, = 76.9 = 498 - 14.7 = 98% = 0.98 At 98% confidence interval tis C = 98% = 0.98 UXO с = 0.02 X = 1-C = (-0.98 0.01 old 0.02 2 = -1 = 498-1 = 497 t , d. f. t 0.01, 497 = 2.334 (using t table) ta Maεgin of etto e E = def. com) 2 - 2.334 14.7 1498) = 1.536 98% confidence interval mean is Ž I E X-E <u<x+E 76.9 -1.5366< 76.9 +1:536 75.364 <e < 78.436 (75.4, 78.4 75.4<u< 178.4