The price of a notebook has dropped to $3.20 today. yesterday's price was $3.45 . find the percentage decrease.

If set d is not the empty set but is a subset of set e, then which of the following is true? d ∩ e = d d ∩ e = e d ∩ e = ∅

Jacob is graphing the line represented by the equation  −6x−5y=12.−6x−5y=12.  he first plots the  x-x-  and  y-interceptsy-intercepts  as follows.    which statement is correct regarding the intercepts on the graph?

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).