A new medical test is designed to quickly detect whether someone is infected by SARS or not. The test result could be either positive or negative. A group of1250 persons have gone through the test among which 1175 are free of SARS infection. Among the 1175 healthy people, 1170 of them return negative test results; while among the remaining infected people, 73 of them return positive test results. Based on the above information, if positive test result is returned for another person, is he/she infected by SARS or not?

A new medical test is designed to quickly detect whether someone is infected by SARS or not. The test result could be either positive or negative. A group of1250 persons have gone through the test among which 1175 are free of SARS infection. Among the 1175 healthy people, 1170 of them return negative test results; while among the remaining infected people, 73 of them return positive test results. Based on the above information, if positive test result is returned for another person, is he/she infected by SARS or not?

A First Course in Probability (10th Edition)

10th Edition

ISBN:9780134753119

Author:Sheldon Ross

Publisher:Sheldon Ross

Chapter1: Combinatorial Analysis

Section: Chapter Questions

Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...

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Each year, over 2 million people in the United States become infected with bacteria that are resistant to antibiotics. In particular, the Centers of Disease Control and Prevention has launched studies of drug-resistant gonorrhea (CDC.gov website). Of 142 cases tested in Alabama, 9 were found to be drug-resistant. Of 268 cases tested in Texas, 5 were found to be drug-resistant. Do these data suggest a statistically significant difference between the proportions of drug-resistant cases in the two states? Use a 0.02 level of significance. What is the p-value, and what is your conclusion? Test statistic = (to 2 decimals) p-value = (to 4 decimals) Conclusion: Select your answer - Choose the correct option. There is a significant difference in drug resistance between the two states. Alabama has the higher drug resistance rate. - Select your answer - ▼
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The drug X is marketed to help protect against male pattern baldness, and it also may protect against prostate cancer. A large sampleof healthy men over age 60 were randomly assigned to receive either a daily drug X pill or a placebo. The study lasted nine years and the men had annual check-ups and a biopsy at the end of the study. Prostate cancer was found in 815 of 4368 men taking drug X and in 1176 of the 4698 men taking a placebo. What kind of a study is this and what mesure of assocation (rd, rr, or) can be used and why?
The Consumer Reports Restaurant Customer Satisfaction Survey is based upon 148,599 visits to full-service restaurant chains (Consumer Reports website). One of the variables in the study is meal price, the average amount paid per person for dinner and drinks, minus the tip. Suppose a reporter for the Sun Coast Times thought that it would be of interest to her readers to conduct a similar study for restaurants located on the Grand Strand section in Myrtle Beach, South Carolina. The reporter selected a sample of 8 seafood restaurants, 8 Italian restaurants, and 8 steakhouses. The following data show the meal prices ($) obtained for the 24 restaurants sampled. Use a = 0.05 to test whether there is a significant difference among the mean meal price for the three types of restaurants. Please answer the questions in the image.
A researcher wanted to test whether people tended to trust people who smiled more than people who did not smile. To test that, she collected a sample of fifty people and presented each of them with 48 pairings of photos. Each pairing was made of one photo of a smiling person, and another photo of a person who was not smiling. The subjects were asked to select the person they trusted more. For each subject, the researcher measured the number of times a smiling person was selected. Based on the null hypothesis, what should be the mean number of times a smiling person is selected? 1. 48 2. 25 3. 50 4. 24
People who work out vigorously for an hour or more experience loss of electrolytes such as calcium, potassium, and sodium that are released from the body by sweat. Potassium is a very important part of many bodily functions for athletes, including transmitting nerve signals and fluid balance. A random sample of 9 athletes were given water after a vigorous one-hour workout and their electrolytes were then checked and recorded. After another vigorous one-hour workout on a different day, the same 9 athletes’ electrolytes were checked after being given a sports drink. Their potassium levels are given below. Do sports drinks help replenish lost potassium levels more than water after a vigorous workout? Refer to the table below. Water: 4.17, 2.88, 4.71, 4.79, 5.11, 4.12, 3.95, 4.22, 3.86 Sports Drink: 4.20, 3.30, 4.69, 4.82, 5.17, 4.08, 4.49, 4.54,3.71 hypothesis test needed Hypothesis test needed
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The national Park service monitors streams in Rainier national park for pollution and fish spawning habits. Suppose it is known that 40% of the streams in the park are either considered "polluted" or "known for spawning stream", 15% of the streams are classified as "polluted" and 35% of the streams are "known for spawning streams" what proportion of streams are known to be both polluted and known for spawning streams.