9. (a) Find the mean, median, mode and standard deviation of the following set of ungrouped sample data: 4, 2, 3,5, 3, 1, 6, 4, 2, 3 (b) What proportion of the measurements lies within 1 standard deviation of the mean? Within 2 standard deviations of the mean? Within 3 standard deviations? (c) Based on your answers to part (b), would you conjecture that the histogram is approximately bell shaped? Explain. (d) To confirm your conjecture, construct a histogram with class interval width 1, starting at 0.5.