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)

c) 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.