Question

According to the US blood bank about 35.7% of the US has A positive blood. 1. If 3 people are chosen at random then what is the probability that no one has A positive blood?2. If 3 people are chosen at random then what is the probability that all 3 have A positive blood?Show all your work and make sure to round your answer to 3 decimal places.

Answer 1

The percentage of the people that have A positive blood is 35.7%,

`35.7\text{ \%=}(35.7)/(100)=0.357`

The probability of the people that do not have A positive blood,

`1-0.357=0.643`

The probability of people with A positive blood is 0.357

The probability of people without A positive blood is 0.643

1) The probability that 3 people that do not have A positive blood

`\begin{gathered} =0.643*0.643*0.643 \\ =0.2658\approx0.266(nearest\text{ 3decimal places)} \end{gathered}`

2) The probability that 3 people have A positive blood

`\begin{gathered} =0.357*0.357*0.357 \\ =0.0455\approx0.046(nearest\text{ 3decimal places)} \end{gathered}`