Call/WhatsApp/Text +1(838)201-9170

Call/WhatsApp/Text +1(838)201-9170

Call/WhatsApp/Text +1(838)201-9170

At the end of a study, what does it mean to reject the null hypothesis?

1. At the end of a study, what does it mean to reject the null hypothesis?

2. Imagine you are conducting a study to see if students who attend a review session perform better on an exam. What would be the null hypothesis? What would be the research hypothesis? What would be a directional hypothesis?

3. Explain how type I and type II errors relate to the null hypothesis.

4. Researchers are conducting a study of 20 patients to see if a medication would improve the reduce the pain of patients. Half of them receive the medication whereas half receive a placebo. Those that receive the medicine experienced reduced symptoms of pain.

a. What is the population of interest and what is the sample in this study?

b. Was random sampling likely used? Explain why or why not.

c. Was random assignment likely used? Explain why or why not.

d. What are the independent and dependent variables?

e. What is the null hypothesis and what is the research hypothesis?

f. What decision did the researchers make? Use the language of inferential statistics?

g. If the researchers are incorrect what type of error did they make? Explain. What are the consequences of making this kind of error?

5. Read the following statements. If we assume they are all incorrect what type of errors are being made in each (type I or type II)?

a. When false information is repeated several times, people seem more likely, on average to develop false memories than if the

information was not repeated

b. Therapy clients with major depressive disorders who have ongoing structured assessments of their therapy seem to have lower post therapy depression levels, on average, then clients who do not have ongoing structured assessments.

c. Employee morale does not seem to be different on average whether employees work in cubicles or enclosed offices

d. A child’s native language does not seem to be different in strength, on average, whether the child is raised to be bilingual or

not

6. What are the main ideas behind the central limit theorem?

7. What is wrong about the following statement: the central limit theorem states that for a large n, the population mean is approximately normal

8. A study on total sleep time of college students found total sleep time to be approximately normal. The mean (µ) is 6.78 hours, and the standard deviation (σ) is 1.24 hours, and n=120. We want to compute the average total of sleep time.

a. What is the standard deviation for the average time?

b. What is the average that your probability will be below 6.9 hours?

9. Explain what is wrong with the following statements

a. In the binomial se\ng X is a proportion

b. The variance of a binomial is

c. The normal approximation to the binomial distribution is always accurate when n is greater than 1000

d. We can use the binomial distribution to approximate the sampling distribution of when we draw a stratified random sample of

n=50 students from a population of 500 p(1 − p)/n pˇ