Mth 399 week 6 lab work (2017 version)


MATH 399N Statistics for Decision Making 

Week 6 I Lab


Statistical Concepts:

· Data Simulation

· Confidence Intervals

· Normal Probabilities

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 then find the maximum error. Then we can use a calculator to find the interval, (x – E, x + E).

First, find the mean. Under that column, in cell E37, type =AVERAGE (E2:E36). Under that in cell E38, type =STDEV (E2:E36). Now we can find the maximum error of the confidence interval. To find the maximum error, we use the “confidence” formula. In cell E39, type =CONFIDENCE.NORM (0.05, E38, 35). The 0.05 is based on the confidence level of 95%, the E38 is the standard deviation, and 35 is the number in our sample. You then need to calculate the confidence interval by using a calculator to subtract the maximum error from the mean (x-E) and add it to the mean (x+E).

1. Give and interpret the 95% confidence interval for the hours of sleep a student gets. (5 points)


Then, you can go down to cell E40 and type =CONFIDENCE.NORM (0.01, E38, 35) to find the maximum error for a 99% confidence interval. Again, you would need to use a calculator to subtract this and add this to the mean to find the actual confidence interval.

2. Give and interpret the 99% confidence interval for the hours of sleep a student gets. (5 points)


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. (10 points)


4. Find the mean and standard deviation of the DRIVE variable by using =AVERAGE (A2:A36) and =STDEV (A2:A36). Assuming that this variable is normally distributed, what percentage of data would you predict would be less than 40 miles? This would be based on the calculated probability. Use the formula =NORM.DIST (40, mean, stdev, TRUE). Now determine the percentage of data points in the dataset that fall within this range. 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? (15 points)



5. 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? Subtract the probabilities found through =NORM.DIST (70, mean, stdev, TRUE) and =NORM.DIST (40, mean, stdev, TRUE) for the “between” probability. To get the probability of over 70, use the same =NORM.DIST (70, mean, stdev, TRUE) and then subtract the result from 1 to get “more than”. 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? (15 points)


Order a unique copy of this paper
(550 words)

Approximate price: $22

Basic features
  • Free title page and bibliography
  • Unlimited revisions
  • Plagiarism-free guarantee
  • Money-back guarantee
  • 24/7 support
On-demand options
  • Writer’s samples
  • Part-by-part delivery
  • Overnight delivery
  • Copies of used sources
  • Expert Proofreading
Paper format
  • 275 words per page
  • 12 pt Arial/Times New Roman
  • Double line spacing
  • Any citation style (APA, MLA, Chicago/Turabian, Harvard)

Our Guarantees is always working towards customer satisfaction. Our professional academic writers always aim at producing comprehensive papers that possess quality and originality at pocket-friendly prices. Students are assured that all their private information is safe with us.

Money-Back Guarantee provides a system where students can request for money-back in case they cancel the order or in the rare instances of dissatisfaction. The refund policy adheres to the company’s term and conditions on money-back.

Read more

Zero-Plagiarism Guarantee

While providing the best professional essay writing services, we guarantee all our students of plagiarism-free papers. All papers produced by our professional academic writers are checked against all web resources and previously completed papers to avoid plagiarism.

Read more

Free Revision Policy

In our urge to provide the best professional essay writing services, we guarantee students of free revision policy. The free revision policy is a courtesy service where students can request for unlimited for their completed papers. We always aim at achieving 100% customer satisfaction rates. The free revision policy is one among many of our major advantages.

Read more

Privacy Policy

At, every student is entitled to total security. Our professional academic writers are always committed to protecting all private information of our customers. We do not share any personal information with third parties. Additionally, we provide safe systems for all online transactions.

Read more

Fair-Cooperation Guarantee

Working with us is the greatest step towards achieving all your academic goals. We always deliver the best professional essay writing services as promised. We, therefore, expect all students to work cooperatively with us, as we work towards achieving our goal, your satisfaction. This way, all services will be delivered accurately and on time.

Read more

Calculate the price of your order

550 words
We'll send you the first draft for approval by September 11, 2018 at 10:52 AM
Total price:
The price is based on these factors:
Academic level
Number of pages