In order to evaluate the rate of error experienced in reading chest X-rays, the following experiment is done. Several people with known tuberculosis (TB) status (through other reliable tests) are subjected to chest X-rays. A technician who is unaware of this status reads the X-ray, and Table 2.4.2 gives the result. Here + X-ray means the technician concluded that the person has TB. Find
Table 2.4.2 Chest X-ray for TB Result

(a) P (TB | +X-ray),
(b) P (+ X-ray | No TB), and
(c) P (No TB | X-ray).

Person with TB Person Without TB Total 27 97 1903 2000 +X-ray 70 1883 20 -X-ray 1945 55 Total