If you are reffering to this dot plot, it would be 13 trees being studied.
SA=4pir^2
78.54km^2=SA
78.54=4pir^2
divide both sides by 4
19.635=pir^2
aprox pi=3.14 so divide both sides by 3.14
6.25318=r^2
sqrt both sides
2.50063=r
round
radius=2.5km
this question is flawed in that it gives the wrong units
answer is the option with 2.5 in it
2nd one
Answer:
The Probability is 63.7%
Step-by-step explanation:
We need to calculate the area of the circle and the area of the square
From the question, we can see that the square is of side 4 √2 cm
The area of the square is simply the square of its side length
We have this as 4√2 * 4√2 = 16 * 2 = 32 cm^2
The area of the circle can be calculated using the formula for the area of a circle, with the radius being 4 cm
So, we have the area of the circle as;
Pi * r^2
= 22/7 * 4 * 4 = 50.3 cm^2
so, to find the probability, we need to divide the area of the circle by the area of the square
we have this as;
32/50.3 = 0.6366
In percentage, we simply multiply by 100% to give
0.6366 * 100% = 63.66%
To the nearest tenth, this is 63.7%
Basically what you do is (the ^ arrow meaning exponent)
You take 3.7 + 4.45 x 10^20
Then 8.15 x 10^20, remove the decimal of 8.15 = 815 x 10^-2 x 10^20
815 x 10^18 = <span>815000000000000000000</span>
