Quiz 1 - Introductory Statistics - F24 - B.docx

Introductory Statistics

1. Date: Monday 24/10/2024 Instructor Name: Dr. Amal Mohamed
Name: _________________________ ID: ______________________
Instructions:
1-The Academic Integrity code applies to this test.
2-You have 45 minutes to finish the exam!
PART Question Possible points Score
I MCQs 8
II Question 1 10
Question 2 12
Question 3 9
Question 4 8
Total
Worth 5%
47
BONUS
1%
Question 5 13

2. Part I: Multiple Choice Questions (MCQs)
1.Indicate which of the following variables are quantitative and which are qualitative:
Quantitative Qualitative
a. Colors of cars
b. Number of persons in a family
c. Marital status
d. Time needed to complete a task
e. Number of typing errors in a document
f. The seat number in a movie theater
g. Military Title (Major, Commander,
Captain, and Colonel)
2. There is a relationship between smoking cigarettes and getting emphysema.
A)descriptive statistics
B)inferential statistics
3.From past figures, it is predicted that 31% of the registered voters in California will vote in
the June primary.
A)inferential statistics
B)descriptive statistics
4. Field position of a football player (goalkeeper, forward, midfield, etc)
A) nominal B) ordinal C) interval D) ratio
5. The ratings of a movie ranging from poor to good to excellent
ʺ ʺ ʺ ʺ ʺ ʺ
A) ratio B) ordinal
6. The annual salaries for all teachers in California
C) interval D) nominal
A) interval B) ordinal
7. City traffic during the rush hour (light, medium, heavy)
C) nominal D) ratio
A) ratio B) ordinal C) interval D) nominal
8. On a recent Statistics test, the scores were 61, 66, 68 , 82, 84, 86, 88, 90, 92, and 93. Find
the 20% trimmed mean of this data.
A) 83 B) 77 C) 38.5 D) 85

3. Part II: Free Response Questions
Q1. Recommendations of sugar consumption are no more than 6 teaspoons of sugar daily for
women and 9 for men. Researchers recorded the amount of sugar 20 boys aged 14-18 consumed
in 24-hours to the nearest teaspoon. The following data were obtained:
40 51 65 11
13 26 63 50
26 133 22 31
36 46 32 142
48 50 46 131

(10 pts) Give the quartiles, the IQR, the Box-Plot and detect the outliers for this data. Show your
work.

4. Q2. The long-distance calls made by the employees of a company are normally distributed with a
mean of 6.3 minutes and a standard deviation of 2.2 minutes. Find the probability that a call:
(a) lasts between 4.1 and 8.5 minutes.
(b) lasts more than 10.7 minutes.
(c) lasts less than 1.9 minutes.
(d) How long do the longest 2.5% of calls last?

5. Q3. In a study of crime rates, data from the following variables were recorded: age, gender, race,
education (years), and annual income (gross).
(a)(4 pts) Which of the five variables listed above are:
i.Qualitative?
ii.quantitative?
(b)(5pts) The following is some summary statistics of a sample of size n :
Total
Cases
SumMedian
Standard
Deviation
MinRange
Lower
25%
Percentile
Upper
25%
Percentile
52 2513 50 4.8 38 24 47 52
Complete the following table:
nMeanVarianceMaximum Q1IQR

6. Q4. Highway fuel consumption was measured in a random sample of 22 vehicles. A histogram of
their fuel consumption in miles per gallon appears below.


(c)(4 pts) Describe the shape, approximate center, outliers and spread of this graph. Are there
any outliers? Also, comment on the values of the mean, median. Note: No calculations are
necessary.
(d)(4 pts) If the bar on the far right-hand side of the distribution is removed, will the value of the
mean of the distribution increase, decrease, or stay the same? Explain your answer. Note: No
calculations are necessary.

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7. Q5. The table below shows a summary of the gasoline consumption in MPG (mile per gallon)
for three representative samples of three types of new cars (C1, C2, and C3) in 2016. Some
values in the table are not given.
Car
Mea
n
Media
n
Varianc
e
StdDe
v
Min
Ma
x
Rang
e
IQ
R
Q1 Q3
C1 19.720.1 5.8
14.
5
24.910.4
18.
4
21.
0
C2 18.618.6 0.5 0.7
17.
1
19.92.8 1.1
19.
1
C3 19.719.5 1.1
17.
3
5.5 1.4
19.
0
Type of
Measur
e
Fill in the missing values as well as the type of measure, that is, Center, Position, or Spread?

8. DRAFT