MATH221 Statistics for Decision Making
Week 2 LAB
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 histogram for the variable
Height. 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 Height 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.
3. Create
a scatter plot with the variables of height and money. Copy the height 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.
Calculating
Descriptive Statistics
4. Calculate descriptive statistics for
the variable Height by Gender. Sort the
data by gender by clicking on Data and then Sort. Copy the heights of the males form the data
file into the Descriptive Statistics worksheet of the week 1 Excel file. Type the standard deviations below. These are
sample data. Then from the data file, copy and paste the female data into the
Descriptive Statistics workbook and do the same

Mean

Standard deviation

Females



Males



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.
6. What is seen in the histogram
created for the heights of students in this class (include the shape)? Explain
your answer.
7. What is seen in the scatter plot for
the height and money variables? Explain your answer.
8. Compare the mean for the heights of
males and the mean for the heights of females in these data. Compare the values
and explain what can be concluded based on the numbers.
9. Compare the standard deviation for
the heights of males and the standard deviation for the heights of females in
the class. Compare the values and explain what can be concluded based on the
numbers.
10. Using the empirical rule, 95% of
female heights should be between what two values? Either show work or explain
how your answer was calculated.
11. Using the empirical rule, 68% of male
heights should be between what two values? Either show work or explain how your
answer was calculated.
MATH221 Statistics for Decision Making
Week 4 LAB
Calculating
Binomial Probabilities
NOTE: For question 1, you will be using the same
data file your instructor gave you for the Week 2 Lab.
1.Using the
data file from your instructor (same one you used for the Week 2 Lab),
calculate descriptive statistics for the variable (Coin) where each of the
thirtyfive students in the sample flipped a coin 10 times. Round your answers
to three decimal places and type the mean and the standard deviation in the
grey area below.
Plotting
the Binomial Probabilities
? For the next part of the lab, open
the Week 3 Excel worksheet. This will be
used for the next few questions, rather than the data file used for the first
question.
1. Click on the “binomial tables”
workbook
2.Type in
n=10 and p=0.5; this simulates ten flips of a coin where x is counting the
number of heads that occur throughout the ten flips
3.Create a
scatter plot, either directly in this spreadsheet (if you are comfortable with
those steps), or by using the Week 1 spreadsheet and copying the data from here
onto that sheet (x would be the x variable, and P(X=x) would be the y variable.
4. Repeat steps 2 and 3 with n=10 and
p=0.25
5. Repeat steps 2 and 3 with n=10 and
p=0.75
6. In the end, you will have three
scatter plots for the first question below.
2. Create scatter plots for the
binomial distribution when p=0.50, p=0.25, and p=0.75 (see directions
above). Paste the three scatter plots in
the grey area below.
Calculating
Descriptive Statistics
Short
Answer Writing Assignment – Both the calculated binomial probabilities and the
descriptive statistics from the class database will be used to answer the
following questions. Round all numeric answers
to three decimal places.
3.List the
probability value for each possibility in the binomial experiment calculated at
the beginning of this lab, which was calculated with the probability of a
success being ½. (Complete sentences not necessary; round your answers to three
decimal places.)
P(x=0) P(x=6)
P(x=1) P(x=7)
P(x=2) P(x=8)
P(x=3) P(x=9)
P(x=4) P(x=10)
P(x=5)
4.Give the
probability for the following based on the calculations in question 3 above,
with the probability of a success being ½. (Complete sentences not necessary;
round your answers to three decimal places.)
5.Calculate
(by hand) the mean and standard deviation for the binomial distribution with
the probability of a success being ½ and n = 10. Either show your work or
explain how your answer was calculated. Use these formulas to do the hand
calculations: Mean = np, Standard Deviation =
6.Calculate
(by hand) the mean and standard deviation for the binomial distribution with
the probability of a success being ¼ and n = 10. Write a comparison of these
statistics to those from question 5 in a short paragraph of several complete
sentences. Use these formulas to do the hand calculations: Mean = np, Standard
Deviation =
7.Calculate
(by hand) the mean and standard deviation for the binomial distribution with
the probability of a success being ¾ and n = 10. Write a comparison of these
statistics to those from question 6 in a short paragraph of several complete
sentences. Use these formulas to do the hand calculations: Mean = np, Standard
Deviation =
8.Using all
four of the properties of a Binomial experiment (see page 201 in the textbook)
explain in a short paragraph of several complete sentences why the Coin
variable from the class survey represents a binomial distribution from a
binomial experiment.
9.Compare
the mean and standard deviation for the Coin variable (question 1) with those
of the mean and standard deviation for the binomial distribution that was
calculated by hand in question 5. Explain how they are related in a short
paragraph of several complete sentences.
MATH221 Statistics for Decision Making
Week 6 LAB
Scenario/Summary
Click to
download the Week 6 Lab Document (Links to an external site.) to complete the
lab for this week. All of the directions
are included in the document.
The data
for this lab is distributed by your professor.
The
document includes places where you need to input the answers. Any place where
you see a gray box is where you need to put an answer.
Deliverables
Each
student will submit a lab. Below is the
grading rubric for this assignment.
Category Points % Description
Questions
15 8 points each, 40 total 50% large
and small sample confidence intervals for a mean
Question 6 16 points 20% normal
probabilities compared with data outcomes
Question 7 24 points 30% normal
probabilities compared with data outcomes
Total 80 points 100% A quality lab will meet or exceed all of
the above requirements.
Required
Software
Microsoft
Office: Word and Excel
Use a
personal copy or access the software at https://lab.devry.edu (Links to an
external site.).
Lab Steps
Prepare and
Submit Lab
Open Excel.
Open the
lab Word document.
Follow the
steps in the lab Word document to do calculations in Excel.
Copy and
paste from Excel into the Word document or retype the answer, and then complete
the answers to the questions in complete sentences (fill in each gray box in
the Word document).
Save the
lab Word document, and submit it; no other files should be submitted
Statistical Concepts:
·
Data Simulation
·
Confidence Intervals
·
Normal Probabilities
Short Answer Writing Assignment
All answers should be complete
sentences.
We need to find the confidence interval for the SLEEP
variable. To do this, we need to find
the mean and standard deviation with the Week 1 spreadsheet. Then we can the Week 5 spreadsheet to find
the confidence interval.
First, find the mean and standard deviation by copying the
SLEEP variable and pasting it into the Week 1 spreadsheet. Write down the mean and the sample standard
deviation as well as the count. Open the Week 5 spreadsheet and type in the
values needed in the green cells at the top. The confidence interval is shown
in the yellow cells as the lower limit and the upper limit.
1. Give and interpret the 95%
confidence interval for the hours of sleep a student gets.
Change the confidence level to 99% to find the 99% confidence
interval for the SLEEP variable.
2. Give and interpret the 99%
confidence interval for the hours of sleep a student gets.
3. Compare the 95% and 99%
confidence intervals for the hours of sleep a student gets. Explain the
difference between these intervals and why this difference occurs.
In the Week 2 Lab, you found the mean and the standard
deviation for the HEIGHT variable for both males and females. Use those values for follow these directions
to calculate the numbers again.
(From Week 2 Lab: Calculate descriptive statistics for the
variable Height by Gender. Click on Insert and then Pivot Table. Click in the
top box and select all the data (including labels) from Height through Gender. Also click on “new worksheet” and then OK.
On the right of the new sheet, click on Height and Gender,
making sure that Gender is in the Rows box and Height is in the Values
box. Click on the down arrow next to Height in the Values box and select Value
Field Settings. In the pop up box,
click Averagethen OK.
Write these down. Then click on
the down arrow next to Height in the
Values box again and select Value Field Settings. In the pop up box, click on StdDevthen OK. Write these values
down.)
You will also need the number of males and the number of females
in the dataset. You can either use the
same pivot table created above by selecting Count in the Value Field
Settings, or you can actually count in the dataset.
Then use the Week 5 spreadsheet to calculate the following
confidence intervals. The male
confidence interval would be one calculation in the spreadsheet and the females
would be a second calculation.
4.
Give and
interpret the 95% confidence intervals for males and females on the HEIGHT
variable. Which is wider and why?
5.
Give and
interpret the 99% confidence intervals for males and females on the HEIGHT
variable. Which is wider and why?
6.
Find the mean and standard deviation of the DRIVE
variable by copying that variable into the Week 1 spreadsheet. Use the Week 4 spreadsheet to determine the
percentage of data points from that data set that we would expect to be less
than 40. To find the actual percentage
in the dataset, sort the DRIVE variable and count how many of the data points
are less than 40 out of the total 35 data points. That is the actual percentage. How does this compare with your
prediction?
Mean ______________ Standard deviation
____________________
Predicted percentage
______________________________
Actual percentage _____________________________
Comparison
___________________________________________________
______________________________________________________________

7.
What percentage of data would you predict would be
between 40 and 70 and what percentage would you predict would be more than 70
miles? Use the Week 4 spreadsheet again
to find the percentage of the data set we expect to have values between 40 and
70 as well as for more than 70. Now
determine the percentage of data points in the dataset that fall within this
range, using same strategy as above for counting data points in the data
set. How do each of these compare with
your prediction and why is there a difference?
Predicted percentage between 40
and 70 ______________________________
Actual percentage
_____________________________________________
Predicted percentage more than 70
miles ________________________________
Actual percentage
___________________________________________
Comparison
____________________________________________________
_______________________________________________________________
Why?
__________________________________________________________
________________________________________________________________
