A medical researcher wondered if there is a significant difference between the mean birth weight of boy and girl babies.Random samples of 5 babies' weights (pounds)for each gender showed the following: To test the researcher's hypothesis,we should use the
A)paired (dependent)samples t-test.
B)independent samples t-test.
C)large-sample z-test.
D)t-test for correlation.

Question

A medical researcher wondered if there is a significant difference between the mean birth weight of boy and girl babies.Random samples of 5 babies' weights (pounds)for each gender showed the following:  To test the researcher's hypothesis,we should use the
A)paired (dependent)samples t-test. 
B)independent samples t-test. 
C)large-sample z-test. 
D)t-test for correlation.

Quizplus · Accepted Answer

The best choice is an independent samples t-test because we are comparing the means of two different groups (boys and girls) and the samples are not related (i.e. each baby's weight is independent of the other babies' weights). A paired (dependent) samples t-test would be used if we were comparing the weights of the same babies before and after a treatment, for example. A large-sample z-test is not appropriate because we have a small sample size (n=5) for each group. A t-test for correlation is not relevant because we are not examining the relationship between two variables, but rather examining the difference between two groups.

A Medical Researcher Wondered If There Is a Significant Difference