Recently an endogenous brain neurotransmitter called gelanin

Recently, an endogenous brain neurotransmitter called gelanin has been discovered; it appears to specifically affect one’s desire to eat food with high fat content. The more of this naturally occurring neurotransmitter an individual produces, the higher is his or her craving for high-fat foods. Recently, a drug company developed an experimental drug that blocks gelanin without affecting the appetite for healthier (less fat) foods. A neuroscientist at the drug company believes that the experimental drug will be very useful for controlling obesity. More specifically, he believes that a daily regimen of the drug will result in eating food with less fat and thereby promote weight loss. An experiment is conducted in which 40 obese female volunteers are randomly assigned to either the drug condition or a placebo condition. Each participant continues the “drug” regimen for a period of six months. At the end of the six months, the mean weight loss of each of the two groups is compared. Which statistical test should be used to analyze these data?

a.) independent samples t-test

b.) one-way analysis of variance (ANOVA)

c.) chi square

d.) related samples t-test

Solution

Here we can use a one-way ANOVA test for the analysis of the given data since if we model in the form of Gauss-Markov linear model ie, Y=Xb+e then here the elements of matrix X are either 0 or 1 ie the drug condition or placebo condition. Further there is one factor ie the weight loss. So a one-way ANOVA test is applied here.