Answer:
4.95%
Explanation:
Given: Dimension of room used for office=

Area of entire home= 2100 feet²
Considering the room is in rectangular in shape.
Now, finding the area of room.
first converting the mixed fraction length to improper fraction.
Dimension=

∴ Dimension=

Area of rectangle=

∴ Area of rectangle=

⇒ Area of rectangle=

Hence area of room used for office is 104.125 feet²
Next, finding the percentage of Kelly´s home is taken up by office.
Percentage of office=

⇒ Percentage of office=

∴ Percentage of office from entire home=

Hence, 4.95% of Kelly´s home is taken up by her office.