In Exercises 9–20, assume that the paired sample data are simple random samples and that the differences have a distribution that is approximately normal.
18. Before/After Treatment Results Captopril is a drug designed to lower systolic blood pressure, when subjects were treated with this drug, their systolic blood pressure readings (in mm Hg) were measured before and after the drug was taken. Results arc given in the accompanying table (based on data from “Essential Hypertension: Effect of an Oral Inhibitor of Angiotensin-Convening Enzyme,” by MacGregor et al., British Medical Journal, Vol. 2). Using a 0.01 significance level, is there sufficient evidence to support the claim that Captopril is effective in lowering systolic blood pressure?
Subject | A | B | C | D | E | F | G | H | I | J | K | L |
Before | 200 | 174 | 198 | 170 | 179 | 182 | 193 | 209 | 185 | 155 | 169 | 210 |
After | 191 | 170 | 177 | 167 | 159 | 151 | 176 | 183 | 159 | 145 | 146 | 177 |
Want to see the full answer?
Check out a sample textbook solutionChapter 9 Solutions
Elementary Statistics
- Nexium is a drug that can be used to reduce the acid produced by the body and heal damage to the esophagus. A researcher wants to estimate the proportion of patients taking Nexium that are healed within 8 weeks. A random sample of 224 patients suffering from acid reflux disease is obtained, and 213 of those patients were healed after 8 weeks. a. Identify the population of interest and sample of interest. what is the sample size? b. Describe the parameter of interest. c. Describe the statistic of interest. What value of the statistic obtained?arrow_forwardcm ass 4 q2arrow_forwardCan you please answer all of the questions in the picture please. Explain PLEASE! IT'S EASY TO UNDERTAND. Thank you!arrow_forward
- The table below shows the number of hours per day 11 patients suffered from headaches before and after 7 weeks of soft tissue therapy. At a=0.01, is there enough evidence to conclude that soft tissue therapy helps to reduce the length of time patients suffer from headaches? Assume the samples are random and dependent, and the population is normally distributed. Complete parts (a) through ()- Patient Daily headache hours (before) 2.9 3.2 3.4 1.8 4.4 1.8 3.8 2.5 1.8 3.3 3.8 Daily headache hours (after) 1.7 3.6 22 1.1 1.1 14 3.5 22 1.2 2.9 4.3 123 456 7 89 10 11 Let ua be the hypothesized mean of the patients' daily headache hours before therapy minus their daily headache hours after it. State Ho and H,. Choose the correct answer below. OA Ho: Hsd H, Hg =d 00. Ha: H 20 DE Ho: Hd PPH:"H (b) Find the critical value(s) and identify the rejection region(s). to = 2.764 (Use a comma to separate answers as needed. Type an integer or a decimal. Round to three decimal places as needed) Identify…arrow_forwardThe table below shows the number of hours per day 11 patients suffered from headaches before and after 7 weeks of soft tissue therapy. At a =0.01, is there enough evidence to conclude that soft tissue therapy helps patients suffer from headaches? Assume the samples are random and dependent, and the population is normally distributed. Complete parts (a) through (f). Patient Daily headache hours (before) 2.9 3.2 Daily headache hours (after) 1.7 3.6 2.2 reduce the length of time 1 2 3 4 5 7 8 3.8 2.5 3.5 2.2 1.2 2.9 4.3 9 10 11 e 1.8 3.3 3.8 3.4 1.8 4.4 1.8 1.1 1.1 1.4 (a) Identify the claim and state Ho and H The claim is "The therapy helps to reduce the length of time patients suffer from headaches." Let Ha be the hypothesized mean of the patients' daily headache hours before therapy minus their daily headache hours after it. State Ho and H. Choose the correct answer below. O A. Ho: Ha sd O B. Ho: Hg s0 H H >0 OC. Ho: Hg d O D. Ho: Ha20 OE. Ho Ho =d OF. Ho: Hgzdarrow_forwardPerform a chi-square analysis using the expected and observed data in Data Table 19. Calculate chi-squared (X2). Show your work in Panel 5. asap pleasearrow_forward
- 4. Measuring the Gadgets Usage of Children at Home during Quarantine Statistical Test/s: Explanation: 10:56 AM 4/4arrow_forwardRefer to the data in images. Test for a significant difference in the variances of theinitial white blood cell count between patients who did andpatients who did not receive a bacterial culture.arrow_forwardA sample of 3 measurements are taken and recorded: a =8, y = 10 and z = 7 The sample mean is: x = = 8.33 Fill in the table below. aj (a; - x)2 Ex: 5.34 Ex: 5.34 Ex: 5.34 82 = (z-z)*+(y-a)* +(z-z) Ex: 5.34 (z-2)*+(y-z)* +(z-) = Ex: 5.34arrow_forward
- A sociologist wants to know the proportion of adults with children under the age of 18 that eat dinner together 7 nights a week. A simple random sample of 1, 122 adults with children under the age of 18 was obtained, and 337 of those adults reported eating dinner together with their families 7 nights a week. a. Describe the parameter of interest. b. Describe the statistic of interest. What value of the statistic obtained?arrow_forwardHow heavy a load (pounds) is needed to pull apart pieces of Douglas fir 4 inches long and 1.5 inches square? Students doing a laboratory exercise sample 20 pieces of wood and find an average load capacity of 30,841 pounds. We are willing to regard the wood pieces prepared for the lab session as an SRS of all similar pieces of Douglas fir. Engineers also commonly assume the characteristics of materials vary normally. Suppose that the strength of pieces of wood like these follow a normal distribution with a population standard deviation of 3,000 pounds (As you can see all three necessary assumptions are met). a. Assuming that all evergreen wood has a known "load" capacity average of 30,000 pounds. Make a two-sided hypothesis (null and alternative statement) about Douglas Fir "load" capacity compared to the overall average. b. Apply the formula for finding our test statistic (show your work or describe the process) Specifically, use the formula for the z-statistic (pasted below and on…arrow_forwardFind the variance and the standard deviation for x and y in Table 1arrow_forward
- Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw HillBig Ideas Math A Bridge To Success Algebra 1: Stu...AlgebraISBN:9781680331141Author:HOUGHTON MIFFLIN HARCOURTPublisher:Houghton Mifflin Harcourt