In a study of the oral home care practice and reasons for seeking dental care among individuals on renal dialysis, Atassi (A-1) studied 90 subjects on renal dialysis. The oral hygiene status of all subjects was examined using a plaque index with a range of 0 to 3 ( soft plaque deposits, abundance of soft plaque deposits). The following table shows the plaque index scores for all 90 subjects.

1.17; 2.50; 2.00; 2.33; 1.67; 1.33; 1.17; 2.17; 2.17; 1.33; 2.17; 2.00; 2.17; 1.17; 2.50; 2.00; 1.50; 1.50; 1.00; 2.17; 2.17; 1.67; 2.00; 2.00; 1.33; 2.17; 2.83; 1.50; 2.50; 2.33; 0.33; 2.17; 1.83; 2.00; 2.17; 2.00; 1.00; 2.17; 2.17; 1.33; 2.17; 2.50; 0.83; 1.17; 2.17; 2.50; 2.00; 2.50; 0.50; 1.50; 2.00; 2.00; 2.00; 2.00; 1.17; 1.33; 1.67; 2.17; 1.50; 2.00; 1.67; 0.33; 1.50; 2.17; 2.33; 2.33; 1.17; 0.00; 1.50; 2.33; 1.83; 2.67; 0.83; 1.17; 1.50; 2.17; 2.67; 1.50; 2.00; 2.17; 1.33; 2.00; 2.33; 2.00; 2.17; 2.17; 2.00; 2.17; 2.00; 2.17;

This project has two parts.

Part I. Confidence Interval on the Mean.

Show the sample data. Describe the purpose for computing a confidence interval for the mean. (What you are setting out to find) Pick a confidence level of your choice.

• Compute a sample mean.
• Describe the variable.
• Describe the confidence level you are taking and its specific meaning.
• Show the confidence interval formula that you are using.
• Show the reliability coefficient (critical value).
• Show all the pertinent computations using the equation editor.
• Draw a conclusion in the context of the experiment.

Part II. Confidence Interval on the Proportion.

Show the sample data. Describe the purpose for computing a confidence interval on the Proportion (What you are setting out to obtain) Pick a confidence level of your choice.

• Compute a sample proportion of your choice (pick a certain index, count how many times it comes up in the sample, divide this frequency by sample size).
• Describe the variable.
• Describe the confidence level you are taking and its specific meaning.
• Show the confidence interval formula that you are using.
• Show the reliability coefficient (critical value).
• Show all the pertinent computations using the equation editor.
• Draw a conclusion in the context of the experiment.