The answer would be: <span>99.0%
</span>
The disease is rare with a prevalence of <span>one out of every thousand people have it. That means, the chance of Roberto has the disease without any test would be 1/1000 or 0.1%
The test sensitivity is 99%, which mean 99% of people with positive test result would have the disease. The chance is should not be influenced by the disease prevalence. </span>
It could be concluded that since line JL is a diameter of a circle, therefore, JK and KL are the tangents of the specific circle that JL is part of. By definition, a tangent is "a line that touches a curve at one point without touching it." Both these lines touches the edges of the circle M therefore they are tangents.