Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Hypothesis testing is one of the mainstays of medical research literature. You would be hard-pressed to find a research article in a clinical journal that doesn't contain the results of at least one hypothesis test. So it's important to think critically about hypothesis tests and what they mean--what they can and can't tell us about our data. I've presented three situations below. Write up a brief description of the problem with the conclusion drawn from the hypothesis test.
1. In an observational study of the effect of a physician quality reporting system, the mean age of the patients of physicians participating in the program is 72.675 years, while the mean age of the patients of physicians not participating in the program is 72.950 years. The total sample size is nearly 11,000 patients. The p-value for the hypothesis test that the mean ages are different is 0.001 (Null hypothesis: the difference in mean ages of the two groups is zero; alternative hypothesis: the difference in means is greater than or less than zero). The analyst concludes that the patients of physicians not participating in the program are older than the patients of participating physicians and therefore not a good comparison group for an observational study.
2. A 1999 study looked at the effect of exposure to perchlorate on rats' thyroids. 30 rats were exposed to perchlorate and their thyroids were compared to 30 rats not exposed to perchlorates. Two of the rats exposed to perchlorate were found to have a rare type of thyroid tumor. Zero of the rats not exposed to perchlorate had tumors. The experimenters performed a hypothesis test for the difference in number of tumors and got a p-value of 0.48. They concluded that perchlorate exposure does not cause thyroid tumors in rats.
3. Three psychiatrists studied a sample of schizophrenic and non-schizophrenic people. They measured 77 variables for each subject - religion, family background, childhood experiences etc. They wanted to determine what factors cause people to later become schizophrenic. Using their data they ran 77 hypothesis tests of the significance of the differences between the two groups of subjects, and found 2 significant at the 2% level. They immediately published their findings.
A researcher collected sample data for 17 women ages 18 to 24 . The sample had a mean serum cholesterol level (measured in mg/100 mL) of 188.8 , with a standard deviation of 5.5.
Construct a 95 percent confidence interval for the true mean order size. (b) How could the confidence interval be made narrower? (c) Do you think the population is normal?
At the .10 level of significance, is the coin biased toward heads? Show your decision rule and calculations.
What is the predicted GPA if a person watches 12 hours of television per week?
How many commercials' worth of data do I need to have a margin of error no more than 3, the correct set of hypotheses
I am not understanding how to do this question as I am still trying to grasp an understanding of the material. I came across this question at the end of the chapter:
To test the effectiveness of a new studying strategy, a teacher randomly divides a sample of 8 students into tow groups, with n = 4 in each group.
Suppose that the probability of strong demand is 0.8 and the probability of weak demand is 0.2. What is the optimal decision using the expected value approach?
The z-score of 1.33 tells you that Eric's time to get to work is 1.33 standard deviations from the mean.
Create a dot plot and a box plot to represent this data. If we create a sample by picking every 3rd data from the population, how would your answer to part a change? Show your work
In a study, 37% of adults questioned reported that their health was excellent. A researcher wishes to study the health of people living close to a nuclear power plant.
A high of 10 was possible. A sample of five tests was selected from each group. The test grade results are found below. At the 0.01 level, how many treatments are involved?
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd