In a large sample Mann-Whitney U test in which the sample size from the first population is 30 and the sample size from the second population is 40, which of the following is the expected U value if the null hypothesis of equal median values is true?
A) 1,200
B) 70
C) 35
D) 600

Question

Quizplus · Accepted Answer

The expected value of U under the null hypothesis for a Mann-Whitney U test is calculated using the formula: $U = \frac{n_1 \times n_2}{2}$, where $n_1$ and $n_2$ are the sample sizes from the two populations. Here, $n_1 = 30$ and $n_2 = 40$, so $U = \frac{30 \times 40}{2} = 600$.

In a Large Sample Mann-Whitney U Test in Which the Sample