The 4th grade class experienced a 15% decrease in enrollment. Last year, the 4th grade class had 280 students. How many students are enrolled in the 4th grade class this year?

How to choose the sign of the radical in the denominator of the formula for the distance from a point to a line.

What is the distance between point a and b

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)