(Ross 6.21) Let fX, Y px, yq " # 24xy 0 ď x ď 1, 0 ď y ď 1, 0 ď x ` y ď 1 0 otherwise (a) Show that fX, Y is a joint probability density function. (b) Find the marginal function of Y . (c) Find ErXs. (d) Find ErY s.

step-by-step explanation:

given perimeter: 28cm

length: 9cm

atp,

2(l+w)=p of the reactangle

2(9+x)=28

18+2x=28

2x=28-18

x=10/2

x=5

therefore width is 5 cm

24

step-by-step explanation:

if it takes 8 pounds to make 12 divide 12 by 8 and you get 1.5, 1.5 x 16 = 24

x> 6

step-by-step explanation:

8x+8> 7x+14

8x-7x> 14-8

x> 6

- "runner b is moving at a slower rate."

- "the graphs shown are graphs of distance(km) against time(min).

the slopes of this graphs are are given by:

slope = (change in y)/(change in x)

= (change in distance)/(change in time)

this is the formula for finding the speed. so, the slope of these graphs represent the speed of the runner.

taking each division in the graph to represent 1 on both axis:

runner a ⇒ speed = (2-0)/(1-0)

= 2/1

= 2 km/min

runner b ⇒ speed = (3-0)/(3-0)

= 3/3

= 1 km/min

this shows that   runner b is moving at a slower rate."