Describe the pattern in each sequence and determine the next term of the sequence. The figure shows a sequence from left to right. The first figure from the left is a dot, the second figure has 3 dots in the shape of a triangle, the third figure has 6 dots in the shape of a triangle, and the fourth figure has 10 dots in the shape of a triangle.

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)