+0

expected value

+1
116
6
+85

1. Suppose we have a bag with 10 slips of paper in it. Eight slips have a 3 on them and the other two have a 9 on them.

What is the expected value of the number shown when we draw a single slip of paper?

2. Suppose we have a bag with 10 slips of paper in it. Eight slips have a 3 on them and the other two have a 9 on them.

What is the expected value of the number shown if we add one additional 9 to the bag.

3. Suppose we have a bag with 10 slips of paper in it. Eight slips have a 3 on them and the other two have a 9 on them.

What is the expected value of the number shown if we add two additional 9's (instead of just one) to the bag?

4. Suppose we have a bag with 10 slips of paper in it. Eight slips have a 3 on them and the other two have a 9 on them.

How many 9's do we have to add to make the expected value equal to 6?

Aug 13, 2020
edited by uvacowdo  Aug 13, 2020

#1
+22
+2

I think you were trying to use LaTeX for your numbers, which is really a nice touch, but it isn't showing up.

(It is just a liiiitttle hard to solve math problems where all the numbers are excluded.)

Aug 13, 2020
#2
+85
+1

hehe... i put them now

uvacowdo  Aug 13, 2020
#3
+22
+2

1. Simply average all the numbers: you get 4.2!

Aug 13, 2020
#4
+85
+1

thank you!

if this isnt too much to ask...could you try the others?

uvacowdo  Aug 13, 2020
#5
+22
+2

2. Same thing, average all the numbers with an additional 9. You will get 4.63636363636 or 51/11 .

3. Well, you know the drill  by now; average! When there are two extra 9's, we get 5 as the expected value.

4. When you add 6 extra 9's you get 6 as the expected value.

:D I hope this helps you!

Aug 13, 2020
#6
+85
+1

thanks so much!