Answer:
The approximate value of the area is 
Step-by-step explanation:
we know that
The area of the circle (landing pad) is equal to

we have

substitute

----> exact value of the area
Find the approximate value
assume 
------> approximate value of the area
1.905 rounded to the nearest tenth is 1.9
Answer: 600 students
Step-by-step explanation:
Of the total number of sixth graders who were surveyed, 5% owned birds.
This 5% translated to 30 students.
30 students is therefore 5% of the total number of sixth graders surveyed.
Assume that number to be x:
x * 5% = 30
x = 30 / 5%
= 600 students
x = # of miles
$59.31 = $31 + $0.19x
Subtract $31 from both sides
$28.31 = $0.19x
Divide both sides by $0.19
149 = x
Juan drove 149 miles