Second, the researcher wishes to use graphical descriptive methods to present summaries of the data on each of the two variables: hours worked per week and yearly income, as stored in file HOURSWORKED.xls.

a)The number of observations (n) is 65 individuals. The researcher suggests using 7 class intervals to construct a histogram for each variable. Explain how the researcher would have decided on the number of class intervals (K) as 7.(2 marks)

b)The researcher suggests using class intervals as 10 < X 15, 15 < X 20, ..., 40 < X 45 for the hours per week variable and class intervals 40 < X 45, 45 < X 50, ..., 70 < X 75 for the yearly income variable. Explain how the researcher would have decided the width of the above class intervals (or class width).(2 marks)

Draw and display a histogram for each of the two variables using appropriate BIN values from part (b) and comment on the shape of the two distributions.