Homework Help is Here – Start Your Trial Now!
Math
Statistics
(c) A medical researcher is working on a new treatment for a certain type of cancer. The average survival time after diagnosis on the standard treatment is two years. In an early trial, she tries the new treatment on three subjects who have an average survival time after diagnosis of four years. Although the survival time has doubled, the results are not statistically significant even at the 0.10 significance level. The explanation is

(c) A medical researcher is working on a new treatment for a certain type of cancer. The average survival time after diagnosis on the standard treatment is two years. In an early trial, she tries the new treatment on three subjects who have an average survival time after diagnosis of four years. Although the survival time has doubled, the results are not statistically significant even at the 0.10 significance level. The explanation is

MATLAB: An Introduction with Applications
MATLAB: An Introduction with Applications
6th Edition
ISBN:9781119256830
Author:Amos Gilat
Publisher:Amos Gilat
Chapter1: Starting With Matlab
Section: Chapter Questions
Problem 1P
See similar textbooks
icon
Related questions
Question

Need help with these 

(c) A medical researcher is working on a new treatment for a certain type of cancer. The average survival time after diagnosis on the standard treatment is two years. In an early trial, she tries the new treatment on three subjects who have an average survival time after diagnosis of four years. Although the survival time has doubled, the results are not statistically significant even at the 0.10 significance level. The explanation is - A. the sample size is small. - B. the calculation was in error. The researchers forgot to include the sample size. - C. that although the survival time has doubled, in reality the actual increase is really two years. - D. the placebo effect is present, which limits statistical significance. The correct answer is A. the sample size is small.
Transcribed Image Text:(c) A medical researcher is working on a new treatment for a certain type of cancer. The average survival time after diagnosis on the standard treatment is two years. In an early trial, she tries the new treatment on three subjects who have an average survival time after diagnosis of four years. Although the survival time has doubled, the results are not statistically significant even at the 0.10 significance level. The explanation is - A. the sample size is small. - B. the calculation was in error. The researchers forgot to include the sample size. - C. that although the survival time has doubled, in reality the actual increase is really two years. - D. the placebo effect is present, which limits statistical significance. The correct answer is A. the sample size is small.
(a) The Survey of Study Habits and Attitudes (SSHA) is a psychological test that measures the motivation, attitude, and study habits of college students. Scores range from 0 to 200 and follow (approximately) a normal distribution with mean 115 and standard deviation \( \sigma = 25 \). You suspect that incoming freshmen have a mean \( \mu \) which is different from 115 because they are often excited yet anxious about entering college. To test your suspicion, you test the hypotheses \( H_0 : \mu = 115 \), \( H_a : \mu \neq 115 \). You give the SSHA to 25 students who are incoming freshmen and find their mean score. Based on this, you reject \( H_0 \) at significance level \( \alpha = 0.01 \). Which of the following would be most helpful in assessing the practical significance of your results? - \( \circ \) A. Report the P-value of your test. - \( \circ \) B. Test the hypotheses again, this time using significance level \( \alpha = 0.001 \). - \( \bullet \) C. Construct a 99% confidence interval for \( \mu \) in order to see the magnitude of the difference between 115 and your sample results. - \( \circ \) D. Take another sample and retest just to make sure the results are not due to chance. (b) In testing hypotheses, if the consequences of rejecting the null hypothesis are very serious, we should - \( \circ \) A. insist that the level of significance be smaller than the P-value. - \( \circ \) B. insist that the P-value be smaller than the level of significance. - \( \circ \) C. use a very small level of significance. - \( \bullet \) D. use a very large level of significance.
Transcribed Image Text:(a) The Survey of Study Habits and Attitudes (SSHA) is a psychological test that measures the motivation, attitude, and study habits of college students. Scores range from 0 to 200 and follow (approximately) a normal distribution with mean 115 and standard deviation \( \sigma = 25 \). You suspect that incoming freshmen have a mean \( \mu \) which is different from 115 because they are often excited yet anxious about entering college. To test your suspicion, you test the hypotheses \( H_0 : \mu = 115 \), \( H_a : \mu \neq 115 \). You give the SSHA to 25 students who are incoming freshmen and find their mean score. Based on this, you reject \( H_0 \) at significance level \( \alpha = 0.01 \). Which of the following would be most helpful in assessing the practical significance of your results? - \( \circ \) A. Report the P-value of your test. - \( \circ \) B. Test the hypotheses again, this time using significance level \( \alpha = 0.001 \). - \( \bullet \) C. Construct a 99% confidence interval for \( \mu \) in order to see the magnitude of the difference between 115 and your sample results. - \( \circ \) D. Take another sample and retest just to make sure the results are not due to chance. (b) In testing hypotheses, if the consequences of rejecting the null hypothesis are very serious, we should - \( \circ \) A. insist that the level of significance be smaller than the P-value. - \( \circ \) B. insist that the P-value be smaller than the level of significance. - \( \circ \) C. use a very small level of significance. - \( \bullet \) D. use a very large level of significance.
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 4 steps

SEE SOLUTIONCheck out a sample Q&A here
Blurred answer
Recommended textbooks for you
MATLAB: An Introduction with Applications
MATLAB: An Introduction with Applications
Statistics
ISBN:
9781119256830
Author:
Amos Gilat
Publisher:
John Wiley & Sons Inc
Probability and Statistics for Engineering and th…
Probability and Statistics for Engineering and th…
Statistics
ISBN:
9781305251809
Author:
Jay L. Devore
Publisher:
Cengage Learning
Statistics for The Behavioral Sciences (MindTap C…
Statistics for The Behavioral Sciences (MindTap C…
Statistics
ISBN:
9781305504912
Author:
Frederick J Gravetter, Larry B. Wallnau
Publisher:
Cengage Learning
Elementary Statistics: Picturing the World (7th E…
Elementary Statistics: Picturing the World (7th E…
Statistics
ISBN:
9780134683416
Author:
Ron Larson, Betsy Farber
Publisher:
PEARSON
The Basic Practice of Statistics
The Basic Practice of Statistics
Statistics
ISBN:
9781319042578
Author:
David S. Moore, William I. Notz, Michael A. Fligner
Publisher:
W. H. Freeman
Introduction to the Practice of Statistics
Introduction to the Practice of Statistics
Statistics
ISBN:
9781319013387
Author:
David S. Moore, George P. McCabe, Bruce A. Craig
Publisher:
W. H. Freeman
SEE MORE TEXTBOOKS