1. Last week I felt symptoms consistent with "Schargel" syndrome. Today I bought a standard saliva test for this condition and it came up negative. However, I'm still concerned that I might have this medical problem because the result could have been a false negative. If the sensitivity of the test is Pr{positive resulthaving the disease} = 0.97, and the specificity is Pr{negative result not having the disease}= 0.95, and the proportion of people in the population with "Schargel" syndrome is Pr{having disease} = 0.06; what is the probability that I actually have the disease? (i.e. calculate Pr{having disease negative result} =?) (*** you should use a probability tree***)