NOTE: This is the second part of Assignment 5. Please submit your
answers in a *single* Python file.
Part 2
The questions in Part 2 refer to the data in the file
'fastfood3.csv'. This file has the columns in 'fastfood2.csv'
plus a new column 'satisfaction'. This new column gives the
customer's satisfaction on a scale of 1-10 (10 being most satisfied)
(a) What percentage of customers gave the highest possible satisfaction
rating? What percentage gave the lowest rating?
(b) Determine the mean satisfaction for each day of the week.
(c) The company considers a satisfaction rating of 7 or higher
to indicate a "satisfied" customer. Find a 95% confidence interval
for the proportion of satisfied customers for each of Breakfast,
Lunch, and Dinner.
(d) The company suspects that the time required to fill an order can
influence customer satisfaction. Find a 95% confidence interval
for the proportion of satisfied customers among those whose orders
took no more than 180 seconds to fill. Do the same for those
whose orders too at least 360 seconds to fill.
(e) Company analysts have developed a formula for predicting customer
satisfaction ratings. It is
predicted satisfaction= 4 + 0.002*cost - 0.005*secs + m,
where m = 1 if the meal is Breakfast, and 0 otherwise.
Predict each customer's satisfaction based on this formula, and
add this prediction as a new column on the data frame named
"predsatis". Then compute the mean predicted rating.
(f) For all the customers, find the maximum difference between the
predicted satisfaction rating and the actual satisfaction rating.
(This should be the absolute value of the difference.) Do the same
for the minimum difference, and then find the average of all the
differences.
