3. People with type O-negative blood are universal donors (any patient can receive a transfusion of O-negative blood). Only about 6.6% of the American
population has O-negative blood. If 270 unrelated people give blood in a certain
week, how many of these people do we expect to be universal donors? (Hint:
Remember to convert percent numbers to decimals before multiplying.)
PLEASE HELP

We expect 17.82, that is, approximately 18 people to be universal donors.

Step-by-step explanation:

For each person, there are only two possible outcomes. Either they are universal donors, or they are not. The probability of a person being an universal donor is independent of any other person. This means that we use the binomial probability distribution to solve this question.

Binomial probability distribution

Probability of exactly x sucesses on n repeated trials, with p probability.

Can be approximated to a normal distribution, using the expected value and the standard deviation.

The expected value of the binomial distribution is:

The standard deviation of the binomial distribution is:

Only about 6.6% of the American population has O-negative blood.

This means that

If 270 unrelated people give blood in a certain week, how many of these people do we expect to be universal donors?

This is E(X) when . So

We expect 17.82, that is, approximately 18 people to be universal donors.

the equation cos(35) =a/25 can be used to find the length of bc what is the length of bc? round to the nearest tenth

step-by-step explanation:

not only in mathematics, scientific proof also are required in the other field of science. also maths proofs are of particular structure, containing steps and logics. so proving is like doing science, it is science. that's why it is important to prove. 

an inaccurate proof leads to errors, or stating results that are not accurate.  which wil mess the probelm up you dont want this