Question

Nerve growth factor (NGF) is a protein that has been shown to play a role in the development and maintenance of peripheral sympathetic neurons. One approach to study NGF is to deprive the animal of NGF and study the effect of this deprivation on various cell types. In this study, the effect on the today protein content in the dorsal root ganglia of rats is considered. Two groups of rats are compared: Those born to NGF deficient females (in utero) and those born to normal females but nursed by NGF deficient females (in milk). The data is shown below

In Milk (M): 0.19 , 0.21, 0.21, 0.23, 0.20, 0.22

In Utero( U): 0.12, 0.19, 0.17, 0.20, 0.09, 0.13, 0.21

Researchers are interested in whether the total protein content tends to be higher among rats deprived of NGF in milk.

1. Let Y be total protein content of a randomly selected rat from the in utero population and X be that of a randomly selected rat from the milk population. What is the appropriate alternative hypothesis?
2. Find the value of the Wilcoxon Rank-Sum test statistic

Answer 1

if we are taking confidence interval 0.05 . Then see at 0.05 the Wilcoxon rank sum table. The test statistic would not lie between the range from the table. So we bound to reject the null hypothesis. And we conclude yes. The researcher can accept the alternative hypothesized statement. Check the sum of those rank.