It is proportional because all the points if put in fraction form equals 1/5. For 1 plant, he has 5 roses, and for 2 plants, he has 10 roses. 2/10=1/5. 3/15=1/5. 4/20=1/5. They all have the proportions of 1 plant per every 5 roses
These are the events in the question above:
<span>D - has disease
</span>
<span>H - healthy (does not have disease)
</span>
<span>P - tests positive </span>
<span>It is the probability that a person has the disease AND tests positive divided by the probability that the person tests positive.
</span>
Sick, + [.04*.91] = .0364
<span>Sick, - [.04*.09] = .0036 </span>
Healthy, + [.96*.04] = 0.0384
<span>Healthy, - [.96*.96] = .9216
</span>
.0364 / (.0364 + .0.0384) = 0.487
