Discussion:
Q1. Classify the following as independent or dependent samples:
a. The effectiveness of two blood pressure medicines on two groups of patients.
b. Measures of gas mileage and speed for a group of racecars.
c. Scores of a group of nurses on the NCLEX nursing license exam.
Q2. Answer the following.
a. Explain the difference between testing a single mean and testing the difference between two means.
b. What two assumptions must be met when one is using z test to test differences between two means?
c. When can the sample standard deviations s1 and s2 be used in place of the population standard deviations σ1 and σ2?
Q3. Choose a variable. Before you simulate collecting the data, decide what a likely average might be and list all data in part e.; then complete the following:
a. Write a brief statement of purpose of the study and the population to be studied
b. State the hypotheses for the study
c. Select an α value
d. Display all the raw data
e. Decide which statistical test is appropriate and compute the test statistic (z or t). Find the critical values(s)
f. State the decision and summarize the results in a paragraph.
You may obtain raw data from the random number table in the appendix section of your text or from any other sources; including sources on the World Wide Web.
Q4. Answer each question below.
a. In what ways is the t distribution similar to the standard normal distribution?
b. In what ways is the t distribution different from the standard normal distribution? Please specify how the formula for the t test differs from the formula for the z test?
Q5. Complete the following:
a. Select a variable. Compare the mean of the variable for a sample of 30 for one group with the mean of the variable for a sample of 30 for a second group. Show a hypothetical set of data with a hypothetical mean and standard deviation and show all calculations for conducting a z test with these data.
b. Select a variable. Compare the mean of the variable for a sample of 10 for one group with the mean of the variable for a sample of 10 for a second group. Show a hypothetical set of data with a hypothetical mean and standard deviation and show all calculations for conducting a t test with these data.
c. Select a variable that will enable you to compare proportions of two groups. Use sample sizes of at least 30. Use the z test for proportions to analyze the data.
You may obtain raw data from the random number table in the appendix section of your text or from any other sources; including sources on the World Wide Web.