Which expressions are equivalent to \dfrac{5^2}{5^8} 5 8 5 2 start fraction, 5, squared, divided by, 5, start superscript, 8, end superscript, end fraction ?.

100,000 random people were tested for condition a. roberto's doctor told him he tested positive for condition a. if the test is 99% accurate and condition a is rare—one out of every thousand people have it. what is the probability that testing positive means roberto has condition a? 99.0% 1% 9% 99.9%