Answer:
Major                     %
             %
_________________________________________
Accounting              240              (240/800)*100=30%
Finance                    160               (160/800)*100=20%
Management           320              (320/800)*100=40%
Marketing                80                (80/800)*100= 10%
_________________________________________
Total                         800                     100%
Step-by-step explanation:
For this case we can create the following table calculating the percent frequency as:
 
 
Where  represent the number of students for the i category and n the total sample size.
 represent the number of students for the i category and n the total sample size.
Major                     %
             %
_________________________________________
Accounting              240              (240/800)*100=30%
Finance                    160               (160/800)*100=20%
Management           320              (320/800)*100=40%
Marketing                80                (80/800)*100= 10%
_________________________________________
Total                         800                     100%
The pie chart is on the figure attached.  We use excel to create it.