16. A random sample of eight pairs of twins were randomly assigned to treatment

Question

16. A random sample of eight pairs of twins were randomly assigned to treatment A or treatment B. The data are given in the following table. Twins Treatment A 48.3 44.6 49.7 40.5 54.3 55.6 45.8 35.4 Treatment B 43.5 43.8 53.7 43.9 54.4 54.7 45.2 34.4 1 34568 (a) Is there any significant evidence that the two treatment differ using an 0.05 and Wilcoxon-signed rank test. (b) What is the p-value of the Wilcoxon signed rank test. c) Compare the p-value of the Wilcoxon-signed rank test and paired t-test.

Explanation / Answer

The complete R snippet is as shown below

A <- c(48.3,44.6,49.7,40.5,54.3,55.6,45.8,35.4)
B <- c(43.5,43.8,53.7,43.9,54.4,54.7,45.2,34.4)

## wilcox text

wilcox.test(A,B,conf.int = 0.95,paired=TRUE)

#paired test

t.test(A,B,paired = TRUE,conf.level = 0.95)

The results are

wilcox.test(A,B,conf.int = 0.95,paired=TRUE)

   Wilcoxon signed rank test

data: A and B
V = 22, p-value = 0.6406,the result is not signficant as the p value is not less than alpha 0.05
alternative hypothesis: true location shift is not equal to 0
95 percent confidence interval:
-2.05 2.80
sample estimates:
(pseudo)median
0.425

t.test(A,B,paired = TRUE,conf.level = 0.95)

   Paired t-test

data: A and B
t = 0.076822, df = 7, p-value = 0.9409, the result is not signficant as the p value is not less than alpha 0.05
alternative hypothesis: true difference in means is not equal to 0
95 percent confidence interval:
-2.233538 2.383538
sample estimates:
mean of the differences
0.075

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.