Philadelphia University
First Exam D
Department of basic Science and Mathematics
Elementary Probability and Statistics
Student Name:
Student Number:
19/11/2014
Section:
Question one: Choose the correct answer of the following.
1. ___________ is the set of all people (or things) we want to study or have
numerical information about.
a) Inferential statistic.
b) Probability.
c) Population.
d) Data.
2.
a)
b)
c)
d)
Which of the following is true:
The standard deviation of a data set is a measure of position.
The country of birth (Jordan, Syria,..) is kind of quantitative(numerical) variable
A correlation coefficient (r) is always between 0 and 1.
The variance can’t be negative number.
3. If the median of the following set of data is 9.4. The value of x is:
12.9
a)
b)
c)
d)
11.3
x
8.8
9.4
11.3
12.9
7.5
4. Suppose that a frequency distribution is skewed to the left. Which of the following
is possible values of the mean, median and mode?
a)
b)
c)
d)
Mean =50, Median =35, mode = 42.
Mean = 35, Median = 50, mode = 42.
Mean = 35, Median =42, mode =50.
Mean =42, Median = 50, mode =35.
Philadelphia University
First Exam D
Department of basic Science and Mathematics
Elementary Probability and Statistics
Student Name:
Student Number:
19/11/2014
Section:
5. Find 90-percentile (P90) of the data represented in the following stem and leaf
plot
stem
Leaf
4
5
6
23336
01115
567799
a)
b)
c)
d)
69
51
46
67
6. The variance of the data set {11, 11, 11, 11} is
a)
b)
c)
d)
11
-11
44
0
7. The third quartile (Q3) of the data represented in the box plot below is
20
a)
b)
c)
d)
120
40
100
80
40
60
80
100
120
140
160
180
Philadelphia University
First Exam D
Department of basic Science and Mathematics
Elementary Probability and Statistics
Student Name:
Student Number:
19/11/2014
Section:
Question two: For the following frequency distribution table (show your work). Find
Class
Frequency
Relative frequency
[10-20]
[20-30]
[30-40]
[40-50]
[50-60]
6
14
0.12
0.28
Cumulative
frequency
6
20
11
10
0.22
0.20
40
50
A. The relative frequency of the class[30-40]
B. The cumulative frequency of the class [30-40]
Question three: Find the regression line equation of the data, such that
𝐧 = 𝟏𝟎,∑ 𝒙 = 𝟓𝟓, ∑ 𝒚 = 𝟒𝟗, 𝑺𝒙𝒙 = 𝟖𝟐. 𝟓 , 𝑺𝒚𝒚 = 𝟑. 𝟑 , 𝑺𝒙𝒚 = −𝟏𝟔. 𝟓