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KING ABDULAZIZ UNVERSITY
Faculty of Sciences and Arts: Khulais
Time Allowed: 90 Minutes
Date: 23/12/1430H
C
STAT 110 - First Exam
Name:
ID:
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Section:
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You have 30 questions. You have 90 minutes to solve the exam. Please mark all your
answers on the answer sheet provided to you. You have to submit both question paper
and answer sheet but only the answer sheet will be graded.
Please: Make sure that the answer sheet form matches the question form.
Choose the best answer for each of the following questions:
Q.1
If we have measured the weights of a sample of 50 persons and computed their
median, this will be an example of …….. statistics.
(A) predictive (B) inferential (C) descriptive (D) population
Q.2
What is the statistical term for the mean that is obtained by using all data
values of a specific population.
(A) statistic
(B) variable
(C) parameter
(D) quantity
Q.3
If a researcher would like to determine the effect of height on weight, then
weight is called a (an) …….. variable.
(A) independent
(B) dependent
(C) confounding
(D) outcome
Q.4
Eye color (blue, brown, green) is an example of what level of measurement?
(A) ordinal
(B) interval
(C) ratio
(D) nominal
Use the following to answer questions 5 -13:
Suppose that you have the following set of numbers: 4, 6, 3, 7, 2, 1, 5, 4.
Q.5 The Value of the mean is ……..
(A) 6
(B) 4.5 (C) 4
(D) 5
Q.6
The value of the mode is ……..
(A) 4
(B) 5
(C) 7
(D) 8
Q.7
The value of the first quartile (Q1) is ……..
(A) 3.5
(B) 2.5 (C) 3
(D) 2.25
Q.8
The value of the interquartile range (IQR) is ……...
(A) 3
(B) 5
(C) 3.5
(D) 4
Q.9
The value of the variance is ……..
(A) 4
(B) 5.4 (C) 4.5 (D) 6.3
Q.10
The value of the midrange is ……..
(A) 4.5
(B) 3.5 (C) 5
(D) 4
Q.11
The value of the coefficient of variation is ……..
(A) 45.8%
(B) 50%
(C) 60%
(D) 55%
Q.12
The distribution of these data is called …….. distribution.
(A) trimodal
(B) bimodal
(C) multimodal
(D) unimodal
Q.13 From
the values of the mean, median, and mode, you can conclude that the
distribution of these data is ……..
(A) right-skewed
(C) symmetric
(B) positively skewed
(D) left-skewed
Q.14
Except for rounding error, relative frequencies should add up to what sum?
(A) 100
(B) 0
(C) 1
(D) 50
Q.15
If the mean of 20 values is 30, then the sum of the values is ……..
(A) 400
(B) 500
(C) 600
(D) 450
The following is a histogram for the statistics scores of a group of 50 students.
Use this histogram to answer questions 16 -17.
Q.16 The distribution of statistics scores is ……..
(A) positively skewed
(C) negatively skewed
(B) right-skewed
(D) symmetric
Q.17 What do you expect for the values of the mean, median, and mode?
(A) mean = median
(B) mean < median
(C) mean > median
(D) mean = mode
Q.18
If a variable assumes the values 4, 2, 5, and 6, then this variable is a ……..
variable.
(A) continuous and quantitative
(C) discrete and qualitative
(B) continuous
(D) discrete
Q.19
When we want to compare the variability of students' weights and heights, we
should use the ……..
(A) standard deviation (B) range (C) coefficient of variation (D) variance
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Q.20
The most appropriate measure of central tendency for the values 2, 3, 6, and
100 is the ……..
(A) mode
(B) midrange
(C) mean
(D) median
Use the following frequency distribution to answer questions 21 -26.
Class Limits
Frequency
Q.21
20-30 30-40 40-50 50-60 60-70 Total
10
15
12
9
4
50
The number of classes is ……..
(A) 4
(B) 5
(C) 6
(D) 7
Q.22 What is the width of the class 50 -60?
(A) 10
Q.23
Q.24
Q.25
(B) 5
(C) 15
(D) 20
The value of the range is ……..
(A) 55
(B) 40
(C) 50
The modal class is ….….
(A) 20 - 30
(B) 30 - 40
(D) 45
(C) 40 - 50
(D) 60 - 70
Using the class 50 - 60, the lower class boundary, and the class midpoint
are …… and ……, respectively.
(A) 49.75, 55
(B) 49.5, 55
(C) 49.5, 60 (D) 49.75, 50
Q.26 What is the cumulative frequency for the class 50 - 60?
(A) 46
(B) 37
(C) 25
(D) 9
Q.27 When
data are categorized as male and female, the most appropriate measure
of central tendency is the ………
(A) median
(B) mode
(C) midrange
(D) mean
Q.28
If a variable can take any value between 0 and 50, then this variable is called
a …….. variable.
(A) continuous and qualitative
(C) discrete
(B) discrete and quantitative
(D) continuous
Q.29
If a student scored 70 points on a test where the mean was 60 and the student's
z-score was 2, then the standard deviation, s, must be ……..
(A) 3
(B) 4
(C) 2
(D) 5
Q.30
When the distribution is normal or bell-shaped, if a data value is not within the
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range [x – 3s , x + 3s], then this value is called ……..
(A) an outlier (B) the third quartile (C) the first quartile (D) the midrange
Good Luck …..
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Answer Key (Template C)
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