Download Warm Ups 13-4 1. In expansion of (3x

December 08, 2011
Warm Ups 13-4
5
2 3
1. In expansion of (3x - 2y) , find x y term
2. In expansion of (2x3 + 1/x )12, find the constant term.
December 08, 2011
Let X be the sum when you roll 2 die. Make a frequency table for X
x
2
3
4
5
6
7
8
9
10
11
12
P(X=x)
Find (with grapher)
median:
mode:
mean:
variance:
Population standard deviation:
Sample Standard deviation
December 08, 2011
The mean is also called the "expected value" E(X)
mean =
Example: Find k, and then find the mode, median, and mean values
of X in the probability distribution function below. Do this with and
without a grapher.
x
P(X=x)
mode:
median:
mean:
1
1/10
2
2/10
3
4/10
4
k
December 08, 2011
The book gives all sorts of fancy formulas and shortcuts for
finding variance, but since we aren't going to be on this topic for a
long time, let's just keep it simple and use our formula and our
graphers to find variance.
x
-2
P(X=x)
Find (with grapher)
E(X):
standard deviation:
variance:
We could even find
E(2X):
Var(X+3):
Sd(1/X):
-1
0
1
2
December 08, 2011
How many tails would you expect when a coin is tossed 5 times?
Make a probability distribution table and calculate E(X) to back
this up. Would you ever roll this many tails?
x
P(X=x)
0
1
2
3
4
5
December 08, 2011
A dart board consisting of concentric circles of radius 1,2,and 3 units is placed
on a wall. Upon throwing a dart, which lands on some random location on the wall,
a player will receive $8 is the smaller circle is hit, $6 if the middle annular
region is hit, and $4 if the outer annular region is hit. However, should the
player miss the dart board altogether they would lose $7. The probability that
the player misses the dart board and hits the wall is .5
a. How will the player fare in this game? ( i.e. what is the E(X))
8
b. Is it a fair game?
x
P(X=x)
8
6
4
-7
6 4
December 08, 2011
#13-4 p. 541 1-7 skip 3
December 08, 2011