First, the researcher wishes to use the graphical descriptive methods to present the data. He suggests using class intervals such as 0-6, 6-12, 12-18, ... for one variable and class intervals 0-30000, 30000-60000, 60000-90000, ...., for the other variable. Explain how he would decide on the number of classes and the above class intervals. (b) Use appropriate BIN values from part (a) to draw a histogram for each variable and comment on the shape of the two distributions. (C) Use an appropriate plot to investigate the relationship between the two variables. Briefly explain the selection of each variable on the X and Y axes and why? On the same plot, fit a linear trend line including the equation and the coefficient of determination R