Which one of the following is true? Why not the others? a. Histograms are useful for visualizing correlations. b. Pyramid charts are generally preferred to bar

Question

Which one of the following is true? Why not the others?

a. Histograms are useful for visualizing correlations.
b. Pyramid charts are generally preferred to bar charts.
c. A correlation coefficient can be negative.

Answer 1

We can brand option a as false because we know that Histograms only show distribution of data. They are nothing more than frequency plots. So graphs can show you only very general information about your data and are not useful for showing correlations between variables.

 

Option B is a little in the gray area. I would say that it is false. Pyramid charts (assuming we have the same definition) are essentially bar charts that use pyramidal shapes to illustrate the data. They don't actually add any data to the chart that a bar chart wouldn't have. I suppose on some occasions, a pyramid chart might make the data easier to visualize, but that doesn't necessarily mean that they are preferred over bar charts.

 

Option C, however, is true. A correlation coefficient is  measure of the linear relationship between variables, and can have either a positive or negative sign. The sign on such a coefficient refers to the direction of the relationship. A negative sign indicates that as one variable increases, the other decreases. A positive sign indicates that as one variable increases, the other increases as well.