Arrange the steps for calculating Mann Whitney U:
(A) Select the larger of rank totals

(B) Add up ranks for each group independently

(C) Rank all scores together, ignoring which group they belong to

(D) Calculate N1, N2, and NX

(E) Calculate U
Choose the correct answer from the options given below:

Correct option is B

The Mann-Whitney U test is a non-parametric test used to determine whether there is a difference between two independent groups. Here's how the steps logically unfold:
1. (C) Rank all scores together, ignoring which group they belong to
· All the data points from both groups are combined and ranked from lowest to highest. The ranks are assigned without regard to which group the data points come from.
2. (B) Add up ranks for each group independently
· Once the ranks are assigned, you then sum up the ranks for each group separately. This gives you the total rank for each group.
3. (A) Select the larger of rank totals
· After summing the ranks for each group, you identify the larger of the two rank totals. This helps in calculating the U statistic, as it involves comparing the ranks between groups.
4. (D) Calculate N1, N2, and NX
· N1 is the number of observations in Group 1, N2 is the number of observations in Group 2, and NX is the total number of observations across both groups.
5. (E) Calculate U
· Finally, the U statistic is calculated using the rank totals and sample sizes. The U value helps you determine whether there is a significant difference between the two groups.
Information Booster
The Mann-Whitney U test is often used when the assumptions of the t-test (e.g., normality of data) are violated. By ranking the data, it removes the need for assumptions about the distribution, making it more flexible and applicable in various situations. The U statistic calculated is then used to find the p-value, which helps determine whether the observed differences between groups are statistically significant.