A survey of 80 online shoppers was conducted to determine how they rate the quality of service of online retailers. Shoppers were asked to rate the overall service quality from 0 (no quality) to 100 (excellent). The relative frequency distribution for the data (measured in points) was constructed using seven class intervals. Read the intervals as follows: Class Limits [0 to less than 40: Relative frequency = 0.05], Class Limits [40 to less than 50: Relative frequency = 0.10], Class Limits [ 50 to less than 60: Relative frequency = 0.20], Class Limits [ 60 to less than 70: Relative Frequency = 0.275], etc. The relative frequency distribution was graphed: 03 0.25 0.2 Relative Frequency 01 0.05 50 60 70 80 90 100 (Note: IN ORDER TO GET FULL MARKS, SHOW ALL CALCULATION STEPS. FAILURE TO DO SO WILL RESULT IN A SCORE OF "(".) (a) What is the name of this graphical technique? (b) What is the name of another graphical technique that can be used to display relative frequencies? (c) What proportion of the rating points is between 70 and less than 90? How many online shoppers gave the online retailers rating points of less than 60? (d) Assuming that the distribution of the ratings is approximately symmetrical and bell shaped, (i) What is the modal class? (ii) Using the graph above, what are the approximate values of the mean and median? (iii) Take another look at the graph showing the frequency distribution of ratings. Do you detect a flaw in the graph? How do you fix this flaw