Principles of Statistics and Probability (1): Stat-101, Final exam (1432-1)
Majmaa’h University
Time allowed: 2 hrs
Engineering College
1st level
13/2/1432
Answer all the following questions
Question #1:
(5 marks)
Rewrite each the following statements after correction.
a. Grouped data: are presented in the form of a frequency distribution table.
b. Values that are very small or very large relative to the majority of the values in a
data set are called mean values.
c. The mode is the value that occurs with the lowest frequency in a data set
d. The range is obtained by taking the difference between the mean and the median
of the data set.
e. Population variance = 𝑠 2
1
=
∑ 𝑓(𝑚−𝑥̅ )2
𝑛−1
Principles of Statistics and Probability (1): Stat-101, Final exam (1432-1)
Question #2:
(6 marks)
The following table gives the frequency distribution of the number of credit cards
possessed by 80 adults.
a) Prepare a cumulative frequency distribution.
b) Calculate the cumulative relative frequencies and cumulative percentages for
all classes.
Number of Credit Cards Number of Adults
0 to 3
18
4 to 7
28
8 to 11
22
12 to 15
9
16 to 19
3
Round the values of relative frequencies to 3 decimal places
2
Principles of Statistics and Probability (1): Stat-101, Final exam (1432-1)
Question #3:
(5 marks)
The following data give the times (in minutes) taken to commute from home to
work for 20 workers.
10
50
65
33
46
5
11
23
39
26
26
32
19
8
15
19
29
42
21
22
Construct a stem-and-leaf display for these data. Arrange the leaves for each
stem in increasing order. Choose a correct display from the list.
3
Principles of Statistics and Probability (1): Stat-101, Final exam (1432-1)
Question #4:
(8 marks)
The following data give the weights (in pounds) lost by 15 members of a health
club at the end of two months after joining the club.
5 10 8 7 25 12 5 14
11 10 21 9 8 11 18
Construct a box-and-whisker plot. Are the data symmetric or skewed?
4
Principles of Statistics and Probability (1): Stat-101, Final exam (1432-1)
Question #5:
(8 marks)
In a group of people, some are in favor of genetic engineering (F), others are
against (A) and others do not care (D). Three persons are selected at random from
this group and asked whether they are in favor of, or against or they do not care
with genetic engineering. For this experiment
1.
2.
3.
4.
5.
How many simple outcomes are possible?
What is the probability of each simple outcome?
Draw a Venn diagram.
Draw a tree diagram.
List all the outcomes included in each of the following events and find the
probability of each event.
A. All three persons are in favor of genetic engineering.
B. At most one person is against genetic engineering.
C. Exactly two persons are in favor of genetic engineering.
D. At least one person does not care with genetic engineering.
5
Principles of Statistics and Probability (1): Stat-101, Final exam (1432-1)
Question #6:
(8 marks)
The table below shows the results of asking 15 female and 20 male employees
about their opinion in having life insurance. Some said they are in favor, some
against and some are undecided.
In Favor Against Undecided
Male
Female
Total
10
6
4
20
5
7
3
15
15
13
7
35
1. Find all marginal probabilities.
2. Find the conditional probabilities:
A. P(Male/Against).
B. P(undecided/female).
C. P(In Favor/male).
D. P(Female/In favor).
Good Luck
Prof. Dr. Tarek Haweel
Dr. SaMeH Ahmed
6
Total