mjgreatxii
Banned
- Mar 7, 2007
- 2,583
- 153
Guys I have a test in two hours and I have two questions.
I know this isn't really the place but I don't have any study buddies and don't remember this. To preface, I didn't take my final before I went to India in December and I'm taking it now, so this material is from about 3 months ago.
If anybody could help me out I'd appreciate it.
1) Consider a two-sided hypothesis test of H0: B1=0 versus HA: B1 not equal 0.
a. Suppose that the null hypothesis is rejected at the 5% error level, and that this decision or outcome is correct. Illustrate the situation using a drawing of a probability distribution, labeling the drawing carefully. Explain.
b. Now suppose that, once again, the null hypothesis is rejected at the 5% error level, but say this time the decision or outcome is wrong. Illustrate the situation using a drawing of a probability distribution, labeling the drawing carefully. Explain. What kind of error is this?
2) Out of a population of 100,000 people, 30 have a virus.
If you have the virus, and you are tested for it, the test will always tell you that you have the virus (it will come out positive). (This is unrealistic, but it makes the question easier).
If you do not have the virus, there is a 1% chance the test will say you have the virus anyway (a false positive).
a. Draw a decision tree using numerical values to describe the entire situation (you may approximate).
b. If you get a positive result back on the test, what is the chance you have the virus?
c. Does this example illustrate the base rate fallacy? Why or why not?
Thank you Guys!
I know this isn't really the place but I don't have any study buddies and don't remember this. To preface, I didn't take my final before I went to India in December and I'm taking it now, so this material is from about 3 months ago.
If anybody could help me out I'd appreciate it.
1) Consider a two-sided hypothesis test of H0: B1=0 versus HA: B1 not equal 0.
a. Suppose that the null hypothesis is rejected at the 5% error level, and that this decision or outcome is correct. Illustrate the situation using a drawing of a probability distribution, labeling the drawing carefully. Explain.
b. Now suppose that, once again, the null hypothesis is rejected at the 5% error level, but say this time the decision or outcome is wrong. Illustrate the situation using a drawing of a probability distribution, labeling the drawing carefully. Explain. What kind of error is this?
2) Out of a population of 100,000 people, 30 have a virus.
If you have the virus, and you are tested for it, the test will always tell you that you have the virus (it will come out positive). (This is unrealistic, but it makes the question easier).
If you do not have the virus, there is a 1% chance the test will say you have the virus anyway (a false positive).
a. Draw a decision tree using numerical values to describe the entire situation (you may approximate).
b. If you get a positive result back on the test, what is the chance you have the virus?
c. Does this example illustrate the base rate fallacy? Why or why not?
Thank you Guys!
