MATH221 Statistics for Decision Making Week 2 Lab: Excel Analysis

This document presents a completed lab assignment for a Statistics for Decision Making (MATH221) course, focusing on data analysis using Excel. The assignment involves creating various graphs, including pie charts, scatter plots, and histograms, to visualize and interpret survey data. Students are required to calculate descriptive statistics such as mean and standard deviation for variables like sleep and compare results based on gender. The assignment also explores the empirical rule to determine data ranges. Short-answer questions require students to analyze the graphs and provide explanations about the relationships between variables and the shape of the data distribution. The lab covers key statistical concepts like descriptive statistics, graphical representation, and the empirical rule, applying them to real-world survey data.

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MATH221 Statistics for Decision Making
Week 2 Lab
Name: _______________________
Statistical Concepts that you will learn after completing this iLab:
 Using Excel for Statistics
 Graphics
 Descriptive Statistics
 Empirical Rule
Week 2 Lab Instructions-BEGIN
 Data have already been formatted and entered into an Excel worksheet.
 Obtain the data file for this lab from your instructor.
 Use the Week 1 spreadsheet (available from the top of the Week 1 Lesson) for graphs
and calculations. You will need to copy data from the data file into the calculations
spreadsheet to answer some questions.
 The names of each variable from the survey are in the first row of the Worksheet.
This row has a background color of gray to identify it as the variable names. All other
rows of the Worksheet represent a certain students’ answers to the survey questions.
Therefore, the rows are called observations and the columns are called variables. On
page 6 of this lab, you will find a code sheet that identifies the correspondence
between the variable names and the survey questions.
 Follow the directions below and then paste the graphs from Excel in the grey areas
for question 1 through 3. You will be using the Week 1 Excel Sheet for many of the
calculations. Type your answers to questions 4 through 11 where noted in the grey
areas. When asked for explanations, please give thorough, multi-sentence or
paragraph length explanations.
 The completed Lab Word Document with your responses to the 11 questions will be
the ONE and only document submitted to the Week 2: Lab. When saving and
submitting the document, you are required to use the following format: Last Name_
First Name_Week2Lab.
Week 2 Lab Instructions-END

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Creating Graphs
1. Create a pie chart for the variable Car Color: Select the column with the Car variable,
including the title of Car Color. Click on Insert, and then Recommended Charts. It
should show a clustered column and click OK. Once the chart is shown, right click
on the chart (main area) and select Change Chart Type. Select Pie and OK. Click
on the pie slices, right click Add Data Labels, and select Add Data Callouts. Add
an appropriate title. Copy and paste the chart here.
2. Create a scatter plot with the variables of Drive and Money. Copy the Drive variable
from the data file and paste it into the x column in the Scatter Plot worksheet of the
Week 1 Excel file. Copy the Money variable from the data file and paste it into the y
column. Copy and paste the scatter plot below.

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3. Create a histogram for the variable Drive. You need to create a frequency distribution
for the data by hand. Use 5 classes, find the class width, and then create the classes.
Once you have the classes, count how many data points fall within each class. It may
be helpful to sort the data based on the Drive variable first. Once you have the
classes and the frequency counts, put those data into the table in the Freq Distribution
worksheet of the Week 1 Excel file. Copy and paste the graph here.
Calculating Descriptive Statistics
4. Calculate descriptive statistics for the variable Sleep by Gender. Sort the data by
gender by clicking on Data and then Sort. Copy the Sleep of the males from the data
file into the Descriptive Statistics worksheet of the Week 1 Excel file. Type the mean
and standard deviation below. These are sample data. Then, copy and paste the
female data into the Descriptive Statistics workbook and do the same. Keep three
decimal places.
Mean Standard deviation
Females 7.67 1.88
Males 7.76 1.86
Short Answer Writing Assignment
All answers should be complete sentences.
5. What is the most common color of car for students who participated in this survey?
Explain how you arrived at your answer.

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The most common color is gold. The gold is the only color, which takes the maximum
frequency among all the colors. By using the frequency table or pivot table the answer
has been arrived.
6. What is seen in the scatter plot for the Drive and Money variables? Explain your
answer.
There is a positive linear relationship between the drive and the Money. The value of
the R square is 0.5.
7. What is seen in the histogram created for the driving distance of students in this class
(include the shape)? Explain your answer.
The histogram shows that all the data of driving distance is normal. The shape of the
histogram is symmetric, because all of the data are normally and symmetrically
distributed. The maximum frequency has been occurred in the middle part of the
histogram.
8. Compare the mean hours of sleep for males and the mean for females in these data.
Compare the values and explain what can be concluded based on the numbers.
The descriptive statistics table has been shown that the mean hours of sleep for male is
7.76 and for female is 7.67. Hence the mean sleep hours for male is larger than the
female.
9. Compare the standard deviation for the sleep of males and the standard deviation for
the sleep of females in the class. Compare the values and explain what can be
concluded based on the numbers.
The descriptive statistics table has been shown that the standard deviation for the sleep
of male is 1.86 and for female is 1.88. Hence the standard deviation for the sleep hours
of male is lesser than the female.
10. Using the empirical rule, 95% of female sleep amounts should be between what two
values? Either show work or explain how your answer was calculated.
Mean ±2* (standard deviation )
= 7.67±2*(1.88)
= [3.91, 11.42]
11. Using the empirical rule, 68% of male sleep amounts should be between what two
values? Either show work or explain how your answer was calculated.
Mean ±1* (standard deviation)
= 7.76±1*(1.86)
= [5.91, 9.62]

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Code Sheet
Do NOT answer these questions.
The Code Sheet just lists the variables name and the question used by the researchers on
the survey instrument that produced the data that are included in the data file. This is just
information. The first question for the lab is after the code sheet.
Variable Name Question
Drive Question 1 – How long does it take you to drive to the school on
average (to the nearest minute)?
State Question 2 – What state/country were you born?
Temp Question 3 – What is the temperature outside right now?
Rank Question 4 – Rank all of the courses you are currently taking. The
class you look most forward to taking will be ranked one, next two,
and so on. What is the rank assigned to this class?
Height Question 5 – What is your height to the nearest inch?
Shoe Question 6 – What is your shoe size?
Sleep Question 7 – How many hours did you sleep last night?
Gender Question 8 – What is your gender?
Race Question 9 – What is your race?
Car Question 10 – What color of car do you drive?
TV Question 11 – How long (on average) do you spend a day watching
TV?
Money Question 12 – How much money do you have with you right now?
Coin Question 13 – Flip a coin 10 times. How many times did you get
tails?
Die1 Question 14 – Roll a six-sided die 10 times and record the results.
Die2
Die3
Die4
Die5
Die6
Die7
Die8
Die9
Die10