statistics

sxi1033

Fall 2019
Critical Thinking Assignment 1 (50 points)
DUE DATE: OCT 2
INSTRUCTIONS:
In these critical thinking assignments, you are going to perform data analysis by comparing
students who were born outside the USA to students who were born in the USA on several
measures. Specifically, you are going to answer the following research questions:
1.
Do students who were born outside the USA have a higher mean GPA than students who
were born in in the USA?
2.
Do students who were born outside the USA spend more time on their homework than
students who were born in the USA?
3.
Do students who were born outside the USA have a higher mean age than students who
were born in the USA?
4.
Do students who were born outside the USA completed more credit hours than students
who were born in the USA?
In order to answer the research questions above, you will need to select a sample of students who
were born in the USA, and a sample of students who were born outside the USA, and compare
and then answer ALL of the questions which follow.
1.
Go into D2L and open the folder named
STUDENT SURVEY,
then open the file named
STUDENT SURVEY DATA FILE
.
2.
Using the random number generator
http://stattrek.com/Tables/Random.aspx
.
Select a
random sample of 30 students who were born in the USA and a random sample of 30
students who were born outside the USA using the variable “COB” (Country of Birth). The
data file is already sorted by country of birth. Students born outside the USA are listed from
# 1 through #171. Students born in the USA are listed from #172 through #435.
You can also
select your sample by using a systematic random sample but you must clearly specify the
method you used. For example, every 5
th
student, or every 10
th
student, etc.
3.
For each student selected in your samples, list the values for each of the following variables:
a.
Age
b.
Total Credit Hours
c.
GPA
d.
Hours spent on school work at home
Your final data file will look like this: (SEE BELOW)

STUDENT ID
AGE
TOTAL
CRD HRS
GPA
HRS SPENT ON SCHOOL WORK AT
HOME
4.
Using the variable Age, construct TWO frequency distributions to summarize the Ages of
students born in the USA and those born outside the USA.  Use 5 classes to construct your
frequency distribution. For each frequency distribution, show your calculations for the class
width and then list the:
a.
Lower limits and upper limits
b.
Class boundaries
c.
Class mid-points
d.
Relative frequencies
e.
Cumulative frequencies
5.
Using the variable Total Credit Hours, construct TWO frequency distributions to summarize
the total credit hours completed by students born in the USA and those born outside the
USA.  Use 5 classes to construct your frequency distribution. For each frequency
distribution, show your calculations for the class width and then list the:
a.
Lower limits and upper limits
b.
Class boundaries
c.
Class mid-points
d.
Relative frequencies
e.
Cumulative frequencies
6.
Using the variable hours spent on school work at home, construct TWO frequency
distributions to summarize the hours of students born in the USA and those born outside the
USA.  Use 5 classes to construct your frequency distribution. For each frequency
distribution, show your calculations for the class width and then list the:
a.
Lower limits and upper limits
b.
Class boundaries
c.
Class mid-points
d.
Relative frequencies
e.
Cumulative frequencies
7.
Using Excel create six histograms, properly labeled, depicting the data from the frequency
distributions in # 4, #5, and #6 above.
8.
Describe the shape of the data for each of the six histograms. Is it normally distributed?
Positively skewed, negatively skewed, uniform? Or maybe the shape cannot be clearly

determined from your sample data, in which case you would indicate “shape cannot be
determined”.
9.
Make at least one observation about each of the frequency distributions or histograms you
have constructed? For example, with the “ages” of students, you could say that “xx percent
of students born in the USA are less than xx years old. Or you could say that “xx percent of
students born outside the USA have completed between xx and xx credit hours”.
10.