Can a correlation coefficient be determined from a histogram?

Question

If two histograms were made for two paired variables, for example, a histogram for money spent on marketing and a histogram for the revenue gained afterwards, can a correlation analysis be performed? Can I find the correlation coefficient from this?

Answer 1

A correlation coefficient cannot be directly determined from histograms. Histograms are graphical representations of the distribution of individual variables, showing the frequency of data points within specific ranges or bins. They do not preserve the paired nature of data, which is essential for correlation analysis.

To perform a correlation analysis and find the correlation coefficient, you need the paired data points. In your example, you need the pairs of values (money spent on marketing, revenue gained). With this paired data, you can use statistical methods to calculate the correlation coefficient, which measures the strength and direction of the linear relationship between the two variables.

Answer 2

A correlation between two variables cannot be calculated using the information available from the two histograms. A histogram provides only information about one variable such as an approximate median or mean; it provides no information about that variables relationship to another variable.