Devry MATH221 Week 6 LAB Latest 2019 JULY
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
1-5 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  Having Trouble Meeting Your Deadline?Get your assignment on Devry MATH221 Week 6 LAB Latest 2019 JULY completed on time. avoid delay and – ORDER NOW Actual percentage Predicted percentage more than 70 Actual percentage Comparison _______________________________________________________________ Why? ________________________________________________________________ |
