Question

When treating carpal tunnel syndrome, should a patient be treated with surgery or should a splint be applied? In a study of this issue, 73 patients were treated with surgery and 83 were treated with a splint. After 12 months, success was noted in 63 of the surgery patients and 60 of the splint patients. Go through “The Drill” for the data in this exercise. We are interested in any difference either way.

“The Drill” – Confidence Intervals

• Assumptions and Conditions

• Distribution of the sample mean
• Mechanics – computing the confidence interval.
• Interpretation in context .
• Meaning of “We are 95% confident ….”
• Margin of error given the confidence interval.
• Compute a sample size given a margin of error (and other parameters). (1-prop z only)

“The Drill” – Hypothesis Testing

• Assumptions and Conditions (if any additional)
• One or two-sided?
• α-level
• Statement of the Hypothesis
• Distribution of the sample mean under Ho.
• (Make a picture)!
• Mechanics – test statistic
• p-value
• Interpretation in context
• Conclusion
• Type I and Type II error

Answer 1

“The Drill” – Confidence Intervals:

Since each sample size is large and number of successes and failures are greater than 10 in both samples so no assumption needed.

“The Drill” – Hypothesis Testing

Since we reject the null hypothesis so type I error is possible.