13. In 1987. 34.7 million households owned a dog, and 27.7 million 14.1
owned a cat. Since then, dog ownership has decreased by 0.025 0
million households per year, and cat ownership has increased by i
0.375 million households per year. How many years, y, will it b
take for them to be equal?

Anew test for ra is being developed. the test is administered to 750 patients with ra and 750 without ra. for the sake of the question, assume the prevalence of ra in this population is 50%. of the 750 patients with ra, 575 have a positive result. of the 750 patients without ra, 150 have a positive result. what is the positive predictive value of the new test? a575/(575+150) b. 600/(600+ 150) c. 575/(575+125) d. 600/(600+ 125)