Answer:
y6%cf4yergby65thrbgtrvbh
Step-by-step explanation:
Hi there!
The formula to find the are of a circle is :
a =
r²
The formula to find the circumference of a circle is :
c = 2
r
In order to use the area formula, you need to figure out what the radius (r) is.
If we solve for "r" in the circumference equation, we have :
r = c ÷ (2
)
Now we use this to replace "r" in the area formula :
a =
( c ÷ (2
))²
When we simplify this we get :
a = c² ÷ 4
Now you can put your value of "c" into this equation and find "a".
*Remember,
is about 3.1416.
Solving for "a" :
a = c² ÷ 4
a = 28² ÷ 4
28² = 28 × 28 = 784
a = 784 ÷ 4
4
= 4 ×
= 12.56637061435917
a = 784 ÷ 12.56637061435917
a = 62.38873769202297cm²
You need to round to the nearest square centimeter, which means that you need to round to the nearest whole number :
a = 62cm²
There you go! I really hope this helped, if there's anything just let me know! :)
The correct answer would be (C.) x>90
If 25% of the people <em>are</em> vaccinated, then 75% of the people are <em>not</em> vaccinated. Of those not vaccinated, each has a 50% chance of contracting the disease. The probability that someone is both not vaccinated and contracts the disease is (0.75)(0.5)=0.375.
The probability that someone is vaccinated and contracts the disease is (0.25)(0.1)=0.025 (it is multiplied by 0.1 because if the vaccine is 90% effective, then there is a 10% chance someone that is vaccinated can contract the disease.
Add these together for the total: 0.375+0.025=0.4
There is a 40% chance that someone chosen at random will contract the disease.
1.4 x 10 = 14
That's your answer.