Archaeologists often find only parts of ancient human remains. For example, they may find a small finger bone, called the metacarpal bone. Is it possible to predict the height of a human from the length of his or her metacarpal bone? To investigate, a researcher measures the heights and metacarpal lengths of 200 adults. In making the scatterplot, the researcher should
A.
plot the height of the person on the horizontal axis.
B.
plot the metacarpal length on the horizontal axis.
C.
first determine if the heights of humans follow a Normal distribution.
D.
use a plotting scale that makes the overall trend roughly linear.
To investigate whether it is possible to predict the height of a human from the length of their metacarpal bone, the researcher should create a scatterplot of the height and metacarpal length measurements of the 200 adults.
In a scatterplot, we usually plot the independent variable (the one we are using to make predictions) on the horizontal axis and the dependent variable (the one we are trying to predict) on the vertical axis. In this case, the metacarpal length is the independent variable, and the height is the dependent variable.
Therefore, the researcher should plot the metacarpal length on the horizontal axis, which means the correct answer is B.
Additionally, it is important to consider the overall trend of the data points in the scatterplot. If there is a linear relationship between the two variables (metacarpal length and height), it is easier to make predictions. So, the researcher should use a plotting scale that makes the overall trend roughly linear (answer D).
Answer C is not necessary in this case because determining if the heights of humans follow a Normal distribution does not directly relate to creating the scatterplot. However, it could be useful for other analyses.
To summarize, the correct option is B - the researcher should plot the metacarpal length on the horizontal axis, and it would be ideal to use a plotting scale that makes the overall trend roughly linear (answer D).