Wilcoxon signed rank test SolutionWilcoxon signed rank test

Wilcoxon signed rank test

Solution

Wilcoxon signed rank test :

Here hypothesis for test is,

H₀ : Difference between the pairs follows a symmetric distribution around zero.

Vs

H₁ : Difference between the pairs does not follow a symmetric distribution around zero.

For calculating test statistic value we make a table- table1-

Table2-

N_r : Total number of observations = 12.

A test statistic | W | = | -1 - 2 + 3 - 4 + 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12 | = | - 62 | = 62

Table value W_{alpha=0.05,12,two tailed} = 14

Decision : | W | > W_{alpha=0.05,12,two tailed} .

Reject H₀ at 5% level of significance.

Conclusion - Difference between the pairs does not follow a symmetric distribution around zero.

Hence an answer.