math  please check me
posted by Sherrie .
Identify the amount in the following application
In a shipment if 1200 parts, 60 were found to be detective. What percent of the parts were faulty?
a. 60
b. 1200
c. what percent
d. shipment
answer: c
Write the following in the standard form of a number.
Two billion, nine hundred forty million
answer: 2,940,000,000
Flor is putting a fence around a field. The field is rectangular and measures 9.84 yards (yd) long and 18.39 yds wide. How much fence must Flor purchase
a. 28.23
b. 38.07
c. 56.46
d. 46.62
answer: a
Use 3.14 for ï and round your answer to one decimal place.
Find the area of the shaded part. (shaded part is 15ft & 15ft
a. 225.0 ft^2
b. 176.6ft^2
c. 481.5ft^2
d. 48.4ft^2
answer: b
How many grams (g) are there in 7.4 kilograms (kg)? Multiply by 1,000 to make the conversion.
a. 74
b. 7400
c. 740
d. 74,000
answer: b
Write in decimal form
8 583/10,000
a. 85,830
b. 8.583
c. 8.0583
d. 8.00583
answer: c

I don't understand 1.
2 is ok.
3 is incorrect.
4. I don't know the shape of the diagram. If it is a square with 15 ft on a side the area is 225 and you don't need pi in the calculation. If it is a circle with the diameter of 15 ft then the area is 176.7 ft^2.
5. The conversion to grams is ok.
6. I don't see a decimal in 8583/10,000 and that in decimal form is 0.8583 which is not one of the answers.
Have I missed something? 
Write in decimal form. Write answer in lowest terms
8 583/10,000