An ecologist wishes to mark off a circular sampling region having radius 10 m. however, the radius of the resulting region is actually a random variable r with the following pdf.
f(r) = 3/4
1 − (14 − r)2
0
13 ≤ r ≤ 15
what is the expected area of the resulting circular region?

What is (28 + 7 + 6 + 3) x 1/2 show your work

Adepartment store purchases screen-printed t-shirts at a cost of $5 per shirt. they mark up the price 150% (making the selling price 250% of the store's purchase price) and put them on the sales floor. every month that a t-shirt doesn't sell, the store reduces the selling price by 25%.

17. a researcher measures three variables, x, y, and z for each individual in a sample of n = 20. the pearson correlations for this sample are rxy = 0.6, rxz = 0.4, and ryz = 0.7. a. find the partial correlation between x and y, holding z constant. b. find the partial correlation between x and z, holding y constant. (hint: simply switch the labels for the variables y and z to correspond with the labels in the equation.) gravetter, frederick j. statistics for the behavioral sciences (p. 526). cengage learning. kindle edition.