Answer:
0 tests
Yes, this procedure is better on the average than testing everyone, it makes it less cumbersome.
Step-by-step explanation:
Given the information:
Let P be the probability that a randomly selected individual has the disease = 0.1. N individuals are randomly selected, thereafter, blood samples of each person would be tested after combining all specimens. Should in case one person has the disease then it yields a positive result and test should be set for each person.
Let Y be number tests
For n = 3 there are two possibilities. If no one has the disease then the value is 1 otherwise the value is 4, here P = 0.1
Therefore, for Y = 1
P(Y-1) = P(no one has disease)
= 0.9³
= 0.729
If Y = 4
P(Y-4) = 1-P(y = 1)
= 1 - 0.729 = 0.271
The expected number of tests using this formular gives
E(Y) = 1×0.729 + 4×0.271
E(Y) = 0
The area of a circle is equal to the radius squared times pie, basically:

The radius is 3, so we multiply 3 times 3 times pie to get the area.
You're gonna want to plug in the following into a calculator:

After getting 28.26 from such calculator, you need to round to the tenths place. In this number, the tenths place is the 2 next to the decimal on the right. Because the number after the 2 is a 6, that means we need to simplify the answer to (28.3). When you are rounding a number, you look at the number to the right, if it is 5 or bigger, add one and remove the rest, if it is less than 5, just get rid of the rest and leave it as it is.
Y - 4 = 5/2(x + 3)....slope here is 5/2. A perpendicular line will have a negative reciprocal slope. All that means is " flip " the slope and change the sign. So our perpendicular line will have a slope of -2/5 (see how I flipped the slope and changed the sign)
I am not sure what form u need this in...so I will write a few...
point-slope form :
y - y1 = m(x - x1)
slope(m) = -2/5
(-3,4)....x1 = -3 and y1 = 4
now we sub
y - 4 = -2/5(x - (-3) =
y - 4 = -2/5(x + 3) <== point slope form
y - 4 = -2/5(x + 3)
y = -2/5x - 6/5 + 4
y = -2/5x - 6/5 + 20/5
y = -2/5x + 14/5 <== slope intercept form
y = -2/5x + 14/5
2/5x + y = 14/5...multiply by 5
2x + 5y = 14 <== standard form