(Answered) : Dr. Marshall owns a private medical clinic and tries hard to schedule appointments so that patients do not have to wait beyond t

Dr. Marshall owns a private medical clinic and tries hard to schedule appointments so that patients do not have to wait beyond their appointment time. He has the following appointment schedule for the morning of Jan. 13, 2016.

Patient

Scheduled appointment

Time needed (minutes)

Adams

9.30 am

15

Black

9.45 am

20

Coupland

10.15 am

15

Dannon

10.30 am

10

Erving

10.45 am

30

Finn

11.15 am

15

Graham

11.30 am

20

Handfield

11.45 am

15

Ivan

12.00 Noon

15

Jacobs

12.15 pm

15

Unfortunately, not every patient arrives exactly on schedule. Also, some examinations take longer than planned, and some take less time than planned. Marshall’s experience dictates the following: 20% of the patients will be 20 minutes early, 10% of the patients will be 10 minutes early, 40% of the patients will