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.
4500 is the answer to this question.
Answer:
A. The mean is increased by 3
Step-by-step explanation:
2 + 9 + 11 + 10 + 3 + 5 + 4 + 12 = 56/8 = 7
2 + 9 + 11 + 10 + 3 + 5 + 4 + 12 + 34 = 90/9 = 10
10 - 7 = 3
The tax is 3.60, the total is 51.60
Ok so in order to do this, you have to set up an equation. Let's make a=the score of the first test and b=the score of the second test. (You can choose different variables, it doesn't matter.) It says the sum of the two equals 170. So, a+b=170. It also says that the score of the first was 6 less than the second. This can be shown as a=b-6. Now you can plug this in for a in your original equation. It will look like:
(b-6)+b=170
You can solve for b.
2b-6=170
2b=176
b=88
Since you want a, plug into either equation for b. I'll use the second one.
a=88-6
So, a=82
