Correlation, Regression and Normal Distribution Practice Questions

a. The headline of a January 31, 2005 USA Today article read, “‘January Barometer’ predicts a pretty lousy year.” Referring to the stock market (and in particular the S&P 500), the article goes on to say that the month of January was “turning out to be a loser and chances are 2005 will be, too.” To support the claim, the article presents S&P 500 performance data for the past 10 years. Besides the year, the columns are the S&P 500 returns for the month of January and for the entire year.

As you can see, increases (shown in green) in January are typically associated with increases for the full year, while decreases (shown in red) in January are typically coupled with decreases for the full year. There is, however, a possibility that the association that is seen in the data is due to random chance. What could we do to see if the asserted relationship between January returns and the Full Year’s returns is real (i.e., not due only to sampling error)? Using cell Q5, indicate your answer using the number associated with the best choice below.
1. Use Excel’s regression analysis tool to estimate the relationship between the full year’s returns (the dependent variable) and January’s returns (the independent variable). If Significance F value is large (bigger than .05, say), the relationship is real.
2. Use Excel’s regression analysis tool to estimate the relationship between the full year’s returns (the dependent variable) and January’s returns (the independent variable). If the Lower 95% value associated with January’s returns is negative and the upper 95% value is positive, the relationship is real.
3. Draw a scatter diagram with January’s returns on the x-axis and the full year’s returns on the y-axis and use Excel’s Add Trendline feature to estimate the relationship between the two variables. If the slope of the line is not zero, then the relationship is real.
4. Use Excel’s regression analysis tool to estimate the relationship between the full year’s returns (the dependent variable) and January’s returns (the independent variable). If the coefficient associated with January returns is not zero, then the relationship is real.
5. Use Excel’s regression analysis tool to estimate the relationship between the full year’s returns (the dependent variable) and January’s returns (the independent variable). If the p-value associated with January returns is less than our level of significance, the relationship is real.
b. When analyzing the slope in a regression analysis (i.e., the relationship between the dependent variable and one of the independent variables), which of the following would be a Type II error? Indicate your answer in cell Q11.
1. To conclude that the slope (relationship) is not significant when it really is.
2. To conclude that the slope (relationship) is significant when it really is.
3. To conclude that the slope (relationship) is not significant when it really is not.
4. To conclude that the slope (relationship) is significant when it really is not.
5. There cannot be a Type II error in this situation.
c. Which of the following is **not** something we can learn from a scatter plot? Give your answer in cell Q17.
Whether or not there are outliers in the data.
Whether or not there is any relationship between the two variables.
Whether or not there is a curved relationship between the two variables.
Whether or not there is a causal relationship between the two variables.
All of the above can be learned from a scatter plot.

d. The weekly demand for a particular automobile manufacturer follows a normal distribution with a mean of 50,000 cars and a standard deviation of 10,000. There is a 2% chance that this company will sell more than what number of cars during the next week? Report your answer as an integer. Put your answer in cell S23.
e. An automotive repair shop has determined that the average service time on an automobile is 1.5 hours with a standard deviation of 35 minutes. A random sample of 70 services is selected. What is the probability of finding a sample mean of 96 minutes or larger if the population mean is still 1.5 hours? Give your answer to 4 decimal places. Put your answer in cell S24.
f. A news account of a nationwide survey taken by Lou Harris (a well known and reputable opinion polling organization) says 25% of the 1,604 persons responding named the Democrats as the best able to handle the nation’s problems. The news report does not give a margin of error. Based on the information available, compute the margin of error (for 95% confidence). If you believe that there is not enough information to compute the margin of error, enter 0 as your answer. Otherwise, give your answer to 4 decimal places. Put your answer in cell S25.
g. Carpetland salespersons have averaged $8000 per week in sales. Steve Conois, the firm’s vice president, proposes a compensation plan with new selling incentives. Steve hopes that the results of a trial selling period will enable him to conclude (prove) that the compensation plan increases the average sales per salesperson. Which of the following would be a Type I error? Enter your answer in cell S26.
1. To conclude that the average sales per salesperson have not increased when they really have.
2. To conclude that the average sales per salesperson have not increased when they really have not.
3. To conclude that the average sales per salesperson have increased when they really have.
4. To conclude that the average sales per salesperson have increased when they really have not.
5. There cannot be a Type I error in this situation.

h. Consider two experiments. First, from a population that is normally distributed with mean 10, we select one item and find its weight. Let D1 be the distribution of possible outcomes from experiment 1. Second, we take a sample of 5 items from the same population and calculate the average weight of the 5 items. Let D2 be the distribution of possible outcomes (sample averages) resulting from experiment 2. Which of the following statements is true and which is not true? Use cells Q34:Q38 to make your selections.
1. D1 and D2 have the same mean.
2. D1 and D2 are both normally distributed.
3. D1 is wider than D2
4. D1 is narrower than D2
5. D1 and D2 have the same spread (standard deviation)
i. Suppose that we have sampled n observations from a normal distribution and found a 99% confidence interval for a population mean. If the sample size decreases and the confidence level decreases from 99% to 95%, indicate whether the interval will definitely get wider, narrower, or will not be definite either way. Assume that the sample standard deviation remains constant with the new sample size. Use cell Q40.

Calculate the price
Make an order in advance and get the best price
Pages (550 words)
$0.00
*Price with a welcome 15% discount applied.
Pro tip: If you want to save more money and pay the lowest price, you need to set a more extended deadline.
We know how difficult it is to be a student these days. That's why our prices are one of the most affordable on the market, and there are no hidden fees.

Instead, we offer bonuses, discounts, and free services to make your experience outstanding.
How it works
Receive a 100% original paper that will pass Turnitin from a top essay writing service
step 1
Upload your instructions
Fill out the order form and provide paper details. You can even attach screenshots or add additional instructions later. If something is not clear or missing, the writer will contact you for clarification.
Pro service tips
How to get the most out of your experience with TheBestPaperWriters
One writer throughout the entire course
If you like the writer, you can hire them again. Just copy & paste their ID on the order form ("Preferred Writer's ID" field). This way, your vocabulary will be uniform, and the writer will be aware of your needs.
The same paper from different writers
You can order essay or any other work from two different writers to choose the best one or give another version to a friend. This can be done through the add-on "Same paper from another writer."
Copy of sources used by the writer
Our college essay writers work with ScienceDirect and other databases. They can send you articles or materials used in PDF or through screenshots. Just tick the "Copy of sources" field on the order form.
Testimonials
See why 20k+ students have chosen us as their sole writing assistance provider
Check out the latest reviews and opinions submitted by real customers worldwide and make an informed decision.
Psychology
Thanks a lot the paper was excellent
Customer 452453, October 26th, 2022
Architecture, Building and Planning
The assignment was well written and the paper was delivered on time. I really enjoyed your services.
Customer 452441, September 23rd, 2022
Anthropology
excellent loved the services
Customer 452443, September 23rd, 2022
English 101
Very good job. I actually got an A
Customer 452443, September 25th, 2022
Theology
Job well done and completed in a timely fashioned!
Customer 452451, November 18th, 2022
Business Studies
Job well done. Finish paper faster than expected. Thank you!
Customer 452451, October 3rd, 2022
Anthropology
Excellent services will definitely come back
Customer 452441, September 23rd, 2022
Nursing
The paper was EXCELLENT. Thank you
Customer 452449, September 23rd, 2022
11,595
Customer reviews in total
96%
Current satisfaction rate
3 pages
Average paper length
37%
Customers referred by a friend
OUR GIFT TO YOU
15% OFF your first order
Use a coupon FIRST15 and enjoy expert help with any task at the most affordable price.
Claim my 15% OFF Order in Chat