Exam Guideline
*Show all your work*
1.
The percentage of unemployed workers in each of 20 randomly selected cities
are as follows:
3.1
5.4
4.5
3.8
8.2
7.2
1.4
3.8
6.3
4.6
1.8
7.2
2.4
2.5
8.8
4.8
a) Calculate the 20th percentile.
b) Calculate the 40th perc

UNGROUPED DATA
Example Problem: 1,4,1,3,2,1,1
First, rank the data
1, 1, 1, 1, 2, 3, 4
Measures of Central Tendency:
Range = Highest Data Value Lowest Data Value
Mean ( ):
Measures of Variability:
Range = 4-1 = 3
n
Average Deviation (AD):
AD =
n
Where
n

2-4
P
o
si
ti
o
n
:
V
a
l
u
e
:
1
4
2
2
4
4
3
5
6
4
6
2
5
7
7
6
7
9
7
8
4
8
8
9
9
8
9
1
0
9
6
1
1
9
8
1
2
1
3
T
o
t
a
l
9
9
1
0
0
1
0
1
5
a) Mean, = = 78.0769
b) Before finding the median, you should rank the data from the smallest
to the largest first as

Dr. Arizes Classnotes
Page 5-9
Question 14: Suppose that there are two events E1 and E2 such that P (E1) = 0.20 and P
(E2) = 0.30
a) Given that E1 and E2 are independent, what is P (E1 E2)?
P (E1 E2) = P (E1) * P (E2)
= 0.2 * 0.3
= 0.06
b) Given that E1 a

Solution for assigned problems for chapter 4
Page 4-9
Question 4:
X
2
9
13
5
Y
7
4
5
3
XY
14
36
65
15
X2
4
81
169
25
Y2
49
16
25
9
= - 0.1127
= 5.5671
a) b1 = -0.1127, b0 = 5.5671
b) b0 is Y hat () when X = 0. However, note that we must be reasonably sure