Coach increase the number of sit-ups in pe from 40 to 55 by what percent did coach change the number of sit-ups required

Ben is three times as old as samantha, who is two years older than half of michel's age. if michel is 12. how old is ben?

What unit of been sure would be appropriate for the volume of a sphere with a radius of 2 meters

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).