Question

If 1 of the 100 subjects is randomly selected, find the probability of getting someone who did not have a headache.

Answer 1

the data:
10mg Atorvastatin Placebo
Headache 15 65
No Headache 17 3

Answer 2

\[\begin{array}{l|c|c|}
&10\text{mg Atorvastatin}&\text{Placebo}&\color{red}{\text{Total}}\\
\hline
\text{Headache}&15&65&\color{red}{80}\\
\hline
\text{No Headache}&17&3&\color{red}{20}\\
\hline
\color{blue}{\text{Total}}&\color{blue}{32}&\color{blue}{68}&\color{purple}{100}\\
\hline
\end{array}\]
According to the table, 80 of the 100 subjects have a headache. Knowing this, what's the probability that a random subject chosen will have a headache?

Answer 3

I don't know if i'm doing this correctly, but the probability with headache: 80/100 (simplified to 4/5) and with no headache: 20/100 (simplified 1/5).

Answer 4

Yes, \(\dfrac{80}{100}=\dfrac{4}{5}\).