NOT HARD!!

Name_________________________________________________________________

In these problems, you will:

• Identify and write null and research hypotheses

• Make decisions about hypotheses and state conclusions about your research

• Identify differences between one- and two-tailed hypothesis tests

• Identify variables and state hypotheses for your final project

Please answer the following on this page or on additional paper if needed. You must show all of your work to receive full credit for your answers.

• For any math problem, your final answer must be enclosed in a box.

• For any excel problem, follow the directions and upload with problem set

• Your homework must be completed independently, or it is considered academic dishonesty

1. Provide the null hypothesis for the following research hypothesis in words and symbols: Juvenile offenders who complete drug treatment spend fewer number of days clean before relapse than adult offenders who complete drug treatment.

1. If you reject your null hypothesis in Q#1, what can you conclude?

1. You hypothesize that blood alcohol content (BAC) tests that are conducted roadside will have higher values than when the same people have their BAC tested at the hospital later on. Put the research and null hypothesis in symbols.

-If you fail to reject your null hypothesis, what can you conclude?

1. What is the difference between an independent samples t-test and a dependent samples t-test? When would we use each test?

1. What is the difference between a one- and two-tailed hypothesis?

1. What is Type I error?

1. You are interested in knowing if persons who have experienced child abuse have greater mean levels of depression than persons who have not experienced child abuse. You take a sample of 39 victims of child abuse and find that their mean score on a depression scale (with higher scores indicating greater depression) is 14.30 with a standard deviation of 1.79. You take a sample of 24 people who have not experienced child abuse and find that their mean score on a depression scale is 12.13 with a standard deviation of 1.34.

1. 1. Write your null and research hypotheses in symbols.

   2. Is this a directional or non-directional hypothesis?

   3. What are your degrees of freedom?

   4. Calculate an independent samples t test.

   5. Can you reject your null hypothesis? How do you know?

   6. What can you conclude about your research?