The investigators in a study set power at 0.85. Based on this power, which of the following are true?
A. Chances of a Type I error are 15%
B. Probability of finding a significant effect of the treatment under study when there is no effect in reality is 85%
C. Beta in this study equals 20%
D. Chances of a Type II error are 15%
Ans :
D. Chances of a Type II error are 15%
(since P(Type II error) = 1- power)
The investigators in a study set power at 0.85. Based on this power, which of the...
If your study had a power of .80, which of the following statements would be correct? a. There is an 80% chance of committing a Type I error b. There is a 20% chance of committing a Type I error c. There is an 80% chance of finding a relationship or difference that actually exists in the real world. d. There is a .80 probability of correctly failing to reject a true null hypothesis.
C-E needs JMP
Suppose a study is being planned that will investigate whether female Beagles with severe periodontitis (gum and mouth disease) give birth to smaller litters of puppies, on average, than Beagles without periodontitis. Based on previous research, the standard deviation of litter size is estimated to be 2.3 puppies Suppose we suspect that Beagles with periodontitis will give birth to on average 6 puppies whereas Beagles without periodontitis will give birth to on average 5 puppies. a. Using...
Suppose a study is being planned that w investigate whether female Beagles with severe periodontitis (gum and mouth disease) give birth to smaller litters of puppies, on average, than Beagles without periodontitis. Based on previous research, the standard deviation of litter size is estimated to be 2.4 puppies. Suppose we suspect that Beagles with periodontitis will give birth to on average 6 puppies whereas Beagles without periodontitis will give birth to on average 5 puppies a. Using the assumed values...
Based on the power curve shown below, which one of the following statements is false? power 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.0 19 20 21 23 24 25 The probability of a type I error is 0.10 The probability of a type Il error when H 21 is equal to 0.26 The null hypothesis is H0: μ-20 The power of the test when μ-23 is 0.91.
Which of the following statements is FALSE? a.) The power of a hypothesis test is the probability of not making a Type II error. b.) Alpha (α) is equal to the probability of making a Type I error. c.) The probability of rejecting the null hypothesis when the null hypothesis is true is called a Type I Error. d.) A smaller sample size would increase the effectiveness of a hypothesis test.
D Chapter 15 Problem Set Suppose you are planning a study that will est the following one-tailed hypotheses: To evaluate the power of your study, you consider a specific alternative hypothesis, μ-Ha, where μ.> μ。. The following sketch shows two overlapping sampling distributions of X-one when Ho is true (and H1 is false), the other when Hy is true (and Ho is false). The distribution on the left has a mean of yo and represents the sampling distribution of X...
6. Which of the following statements about hypothesis testing are true? • A type I error occurs if H, is rejected when it is true. • A type II error occurs if He is rejected when it is true. • The power of a test is the probability of failing to reject H, when it is false.
6. Which of the following statements about hypothesis testing are true? • A type I error occurs if His rejected when it is true. • A type II error occurs if H, is reject ed when it is true, • The power of a test is the probability of failing to reject H, when it is false,
A random sample of size 295 has x=104. The significance level ? is set at 0.05. The P-value for testing H0: ?=100 against Ha: ??100 is 0.057. Identify all the incorrect statements below regarding this P-value of 0.057. (Select all that apply.) The probability of Type I error equals 0.057. If H0 is true, the probability obtaining a sample mean that would show at least as much evidence against H0 as the observed sample mean is 0.057. The probability that...
An economist wants to study the impact of free financial counseling on saving behavior. The economist has a small random sample of people who have been “rolling over” their credit card debt for six months (i.e. they have not been paying the balance on their credit card, and therefore interest charges have been accumulating). All of these people receive financial counseling. The economist will observe whether or not each of them pays off their credit card debt within six months....