What's the difference between sets of natural numbers and rational numbers?

Will give the box plots below show the math scores of students in two different classes: class a 55 72 75 89 95 class b 55 70 75 94 100 based on the box plots, which statement is correct? a: the median score of class a is greater than the median score of class b. b: the lower quartile of class a is greater than the lower quartile of class b. c: the upper quartile of class a is greater than the upper quartile of class b. d: the maximum score of class a is greater than the maximum score of class b.

Find the sixth term of the following geometric sequence.

The discrete random variables x and y take integer values with joint probability distribution given by f (x, y) = a(y−x+1) 0 ≤ x ≤ y ≤ 2 or =0 otherwise, where a is a constant. 1 tabulate the distribution and show that a = 0.1.2 find the marginal distributions of x and y. 3 calculate cov(x, y).4 state, giving a reason, whether x and y are independent. 5 calculate e(y|x = 1).