Question

A pharmaceutical company believes its Alzheimer’s drug may have an effect on cortical atrophy. If it...

A pharmaceutical company believes its Alzheimer’s drug may have an effect on cortical atrophy. If it
decreases cortical atrophy, it may be a promising candidate for further drug trials; if it increases cortical
atrophy, it may provide insight into the mechanism of Alzheimer’s disease. Thus the company decides
to test the drug on rats, as either result may hold future benefits.
Among 115 transgenic rats (genetically engineered to induce Alzheimer’s), 65 rats receive the drug over
6 months, 50 rats are given placebo, and all rats’ brains are sectioned and stained to measure cortical
atrophy after 6 months. The mean cortical atrophy is 0.25 mm among the rats receiving the drug; the
mean cortical atrophy is 0.29 mm among the rats on placebo.
Suppose that the rats who took the drug had a sample standard deviation of 0.08 and the control rats
had a sample standard deviation of 0.11. Does the mean cortical atrophy differ between the rats who
took the drug and the rats who were on placebo? Test the company’s claim at the α = 0.05 level.
(a) Set up the null and alternative hypothesis (using mathematical notation/numbers AND interpret
them in context of the problem)
(b) Draw a picture of the distribution of the test statistic under H o . Label and provide values for the
critical value and the test statistic, and shade the critical region. (You may want to complete parts
c and d first)
(c) Calculate the test statistic
(d) Calculate the critical value
(e) Make and justify a statistical decision at the α = 0.05 level.
(f) State your conclusions in context of the problem.
(g) Construct a 95% confidence interval for the true difference in cortical atrophy between rats who
took the drug and rats who took the placebo.
(h) Does this interval reaffirm your statistical decision from the hypothesis test? Explain.

0 0
Add a comment Improve this question Transcribed image text
Answer #1

Let , X: Cortial atrophy among the rats receiving the drug Y: Cortial atrophy among the rats on placebo

Add a comment
Know the answer?
Add Answer to:
A pharmaceutical company believes its Alzheimer’s drug may have an effect on cortical atrophy. If it...
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for? Ask your own homework help question. Our experts will answer your question WITHIN MINUTES for Free.
Similar Homework Help Questions
  • 7. A study was conducted to investigate the effectiveness of a new drug for treating Stage...

    7. A study was conducted to investigate the effectiveness of a new drug for treating Stage 4 AIDS patients. A group of AIDS patients was randomly divided into two groups. One group received the new drug; the other group received a placebo. The difference in mean subsequent survival (those with drugs - those without drugs) was found to be 1.04 years and a 95% confidence interval was found to be 1.04 ± 2.37 years. Based upon this information: Select one...

  • 3. A health researcher in a hospital believes that the mean cholesterol level for certain male...

    3. A health researcher in a hospital believes that the mean cholesterol level for certain male population aged-50 is 241. An investigator wishes to examine whether the cholesterol levels are significantly reduced by modifying diet. A random sample of 12 patients agrees to participate in the study and follow the modified diet for 3 months. After 3 months, their cholesterol levels are measured. The mean cholesterol level in the sample is 235 with a standard deviation of 12.5. Based on...

  • A medical researcher wants to determine whether a drug changes the body’s temperature. Seven test subjects...

    A medical researcher wants to determine whether a drug changes the body’s temperature. Seven test subjects are randomly selected, and the body temperature (in degrees Fahrenheit) of each is measured. The subjects are then given the drug and after 20 minutes, the body temperature of each is measured again. The results are listed below. Use significance level α = 0.05, and we assume that the body temperatures are normally distributed. Show your work space provided below: t-Test: Paired Two Sample...

  • A pharmaceutical company claims that its new drug reduces systolic blood pressure. The systolic blood pressure...

    A pharmaceutical company claims that its new drug reduces systolic blood pressure. The systolic blood pressure (in millimeters of mercury) for nine patients before taking the new drug and 2 hours after taking the drug are shown in the table below. Is there enough evidence to support the company's claim? Let d=(blood pressure before taking new drug)−(blood pressure after taking new drug). Use a significance level of α=0.1 for the test. Assume that the systolic blood pressure levels are normally...

  • U Question 8 3 pts Lipitor (atorvastatin) is a drug used to control cholesterol. In clinical...

    U Question 8 3 pts Lipitor (atorvastatin) is a drug used to control cholesterol. In clinical trials of Lipitor, 94 subjects were treated with Lipitor and 270 subjects were given a placebo. Among those treated with Lipitor, 7 developed infections. Among those given a placebo, 27 developed infection. We want to use a 0.05 significance level to test the claim that the rate of infections was the same for those treated with Lipitor as those given a placebo. A What...

  • A pharmaceutical company claims that its new drug reduces systolic blood pressure. The systolic blood pressure...

    A pharmaceutical company claims that its new drug reduces systolic blood pressure. The systolic blood pressure (in millimeters of mercury) for nine patients before taking the new drug and 2 hours after taking the drug are shown in the table below. Is there enough evidence to support the company's claim? Let d = (blood pressure before taking new drug)-(blood pressure after taking new drug). Use a significance level of a = 0.05 for the test. Assume that the systolic blood...

  • 21.HE.B: 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...

    21.HE.B: 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. The results are in the accompanying table on the next page. (a)      Go through “The Drill” for paired t-tests (Use a 0.05 α-level and the corresponding confidence interval.)           The Drill: Assumptions and Conditions Paired Data Condition The data must be paired. Only use pairing if...

  • A drug company developed a honey based liquid medicine designed to calm a chids cough at...

    A drug company developed a honey based liquid medicine designed to calm a chids cough at night. To test the drug. 105 children who were it with an upper respiratory tract infection were randomly selected to participate in a clinical trial. The children were randomly divided into three groups one group was given a dosage of the honey drug the second was given a dosage of liquid DM (an over-the-counter cough medicine), and the third control group) received aliquid placebo...

  • Solve the problem. A drug company developed a honey-based liquid medicine designed to calm a child's...

    Solve the problem. A drug company developed a honey-based liquid medicine designed to calm a child's cough at night. To test the drug, 105 children who were ill with an upper respiratory tract infection were randomly selected to participate in a clinical trial. The children were randomly divided into three groups - one group was given a dosage of the honey drug, the second was given a dosage of liquid DM (an over-the-counter cough medicine), and the third (control group)...

  • A drug company developed a honey-based liquid medicine designed to calm a child's cough at night....

    A drug company developed a honey-based liquid medicine designed to calm a child's cough at night. To test the drug, 105 children who were ill with an upper respiratory tract infection were randomly selected to participate in a clinical trial. The children were randomly divided into three groups - one group was given a dosage of the honey drug, the second was given a dosage of liquid DM (an over-the-counter cough medicine), and the third (control group) received a liquid...

ADVERTISEMENT
Free Homework Help App
Download From Google Play
Scan Your Homework
to Get Instant Free Answers
Need Online Homework Help?
Ask a Question
Get Answers For Free
Most questions answered within 3 hours.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT