Regression Problem- Confim my Anwers Please?

automatic pool cleaner for sale image

sabunabu

Please see the below and my answers-- please let me know if you disagree and also if you know the answers to the 2 questions I don't. Any help is greatly appreciated.

PoolVac, Inc. manufactures and sells a single product called the âSting Ray,â which is a patent-protected automatic cleaning device for swimming pools. PoolVacâs Sting Ray accounts for 65 percent of total industry sales of automatic pool cleaners. Its closest competitor, Howard Industries, has captured 18 percent of the market.

Using the last 26 months of its sales data, PoolVac wishes to estimate demand for its Sting Ray. Demand for Sting Rays is specified to be a linear function of its price (P), average income for households that have swimming pools in the U.S (MAVG) and the price of the competing pool cleaner sold by Howard Industries (PH). The general linear form of the demand function

Qd = a + b P + c MAVG + d PH.

The attached computer printout presents the regression output from 26 observations (monthly data) on the price charged for a Sting Ray (P), average income of households with pools (MAVG), and the price Howard industries charged for its pool cleaner (PH).
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The printout of part of regression output from Minitab for the empirical demand is below:

Regression Analysis: Q versus P, MAVG, PH

Predictor Coef SE Coef T P
Constant 2728.8 531.7 5.13 0.000
P -10.758 1.330 -8.09 0.000
MAVG 0.021420 0.009452 2.27 0.034
PH 3.166 1.344 2.36 0.028

S = 73.0546 R-Sq = 96.6% R-Sq(adj) = 96.2%

Analysis of Variance

Source DF SS MS F P
Regression 3 3379846 1126615 211.10 0.000
Residual Error 22 117414 5337
Total 25 3497260

Source DF Seq SS
P 1 3327368
MAVG 1 22878
PH 1 29600


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1. An estimated demand equation for PoolVac is:
Qd = 2728.8-10.758P+0.021420M+3.166Ph


2. Evaluate the statistical significance of the three estimated slope parameters using a significance level of .05 or 5 percent (you can either use p-values or do a t-test).Please, explain how you decided each parameter was statistically significant or not.

Since the P values of all 3 variables are within the 5% confidence interval, each variable should be considered as staristically significant in determining the demand of the pool vacuums.


3. What is the exact level of statistical significance for estimated slope parameters on price, average income of household and price of related good? Please, explain how you know.

We should look at the P value for each of the slope parameters and in doing so, we find that price is 100% significant, average income (Mavg) is 96.6% (100-.034) and price of competition (Ph) is 97.2% significant (100-.028).


4. Discuss the appropriateness and/or interpretations of the algebraic signs of the three slope parameters, based on your theoretical expectations. Interpret the numerical values of the three slope parameters in the context of this regression.


5. Now evaluate the overall fit of the estimated (sample) regression equation to the data.

a. What percentage of variability in Qd (linear) is explained by a model? Does it indicate a good overall fit? Please, explain.


b. Verify whether the overall regression equation is statistically significant, another words, verify the goodness of overall fit .What is the exact level of significance for the entire regression equation?

Looking at the F stat which is 211.1, we can say the overall regression equation is significant since the absolute value is large. Also, the P value is 0 so there is no chance that this regression equation doesnât explain the relationship between the given variables and quantity demanded.

Answer
All of your answers are good. To say that the F statistic has a large absolute value is a little vague; one would generally either consult an F table to the appropriate threshold value or just look at the P value in the computer output. On the other hand, it isn't wrong, and if your instructor taught it that way you should leave it in.

Regarding the questions you haven't answered, number 4 refers to the direction of the effects on your dependent variable that come with changes in the independent variables. You should look at your coefficients and consider what would happen if you changed the values in your variables. For example, if the price of the product goes up, demand for the product goes down because of the negative coefficient associated with the price variable. If this seems confusing, try plugging in some different values into the equation and calculating the result. The negative coefficient makes sense, because people are going to be less interested in buying something if its more expensive. The question is asking you to evaluate both the actual effects on demand and the expected effects for each of the variables.

Question 5a refers to the R-squared statistic (R-Sq), which is the percent of explained variability as mentioned in the question. Yours is quite high.

During this recession, what do you think of these ideas for saving and making money?

Toilet Pap

1. Set up an apple cider stand on a crisp fall day.
2. Start a gift-wrapping service at the holidays.
3. Sell items from the attic using an on-line auction service.
4. Wear your winter coat one more season
5. Set up an automatic paycheck withdrawal for $2 per week.
6. Hold a garage sale.
7. Barter with neighbors or friends for needed household services.
8. Babysit for neighbors.
9. Mow lawns.
10. Post a flyer at the grocery store offering to help people move.
11. Start a spring cleaning service.
12.Walk dogs.
13. Offer seamstress and tailoring services.
14. Sew instead of buying clothes or home accessories.
15. Provide a taxi service for elderly neighbors.
16. Bike to work.
17. Car pool.
18. Use public transportation.
19. Park in the less expensive lots and enjoy the exercise you get from walking!
20. Conserve electricity at home and estimate monthly savings.
21. Find a student (kindergarten through college) who needs a tutor.
22. Cut out candy and snacks; donate what you save on these purchases and dental bills!
23. Take outgrown kids' clothes to a consignment shop.
24. Take your duds from the '70s or '80s to a vintage shop-everything old is new again!
25. Camp instead of staying in hotels on vacation.
26. Give up cable television for a few months--or forever!
27. Pet sit for neighbors who are traveling.
28. Make Saturday "Homemade Pasta Night" instead of dining out.
29. Borrow the latest best-sellers from the library instead of buying them.
30. Give up soft drinks for a whole summer.
31. Take a Thermos of fresh-brewed coffee to work instead of stopping for gourmet brew.
32. For your birthday, ask friends and family to make a gift to Mennonite Board of Missions, Commission on Overseas Mission, Commision on Home Ministries or Ministries Commission, Mennonite Church Canada in your name.
33. Give up your gym membership for the summer and exercise in the fresh air and sunshine.
34. Use coupons when shopping, and donate the savings.
35. Shop at yard sales and thrift stores--you never know when you'll find a hidden treasure.
36. For large household purchases, look for bargains on-line.
37. Pay off credit card debt so no interest collects.
38. Don't let water run while brushing teeth and turn out lights when you leave a room.
39. Offer your services as an office temp or substitute teacher.
40. Design Web sites for local families and businesses.
41. Buy cost-cutter brands for staples and household supplies.
42. Email friends and family instead of calling.
43. Make your own gift cards for holidays and birthdays.
44. Wear more "hand-me-downs" instead of buying new clothes.
45. Buy clothes that mix-and-match for each season.
46. Start flowers from seeds instead of buying seedlings.
47. Put on a family or neighborhood talent show and charge admission.
48. Use vinegar and water for a general household cleaning solution and save on expensive products.
49. Collect cans.
50. Study your health insurance policy and discover ways to avoid health care costs.
51. Plant a larger garden and sell vegetables at a roadside stand.
52. Instead of taking friends or clients out to dinner, send a donation in their name.
53. Donate your holiday club account and give homemade gifts this year.
54. Instead of buying a new CD every week, trade with your friends.
55. Scale back your vacation this year, or choose a service project instead.
56. Wait another six months for any major household purchase.
57. Postpone an upgrade to a software application you use.
58. Make a choice: Chocolate or coffee. Movies or eating out. Experience the one you choose more fully and donate your savings.
59. Buy a live plant instead of fresh flowers to decorate your table.
60. Love your looks--give up hair color, permanents, and other things that detract from your natural beauty.
61. Learn calligraphy and make money addressing invitations and lettering announcements.
62. For special family nights, plan on a video and pizza at home instead of dinner and a movie out.
63. Take the kids to the grocery store with you instead of hiring a babysitter.
64. Restrict your use of the cellular phone to emergencies only.
65. Choose eyeglasses with a sun clip instead of buying prescription sunglasses.
66. Wait for summer clothes to go on sale.
67. Be creative with leftovers--use them for work lunches.
68. Find loose change and save it in a coffee can for a year.
69. Bathe the dog yourself and save the groomer's costs.
70. Do your own house painting this spring instead of hiring a professional.
71. Play tennis on the public courts and save fees.
72. Give up golf for a few weekends and hike in a state park instead.
73. Rake lawns in your neighborhood in the fall.
74. Donate your expense checks from work-related travel.
75. Hold a bake sale.
76. Have friends over for parlor games instead of going out to the theater or a concert.
77. Shovel snow for money.
78. Organize a neighborhood car wash.
79. Sell lem

Answer
wow these are all really good ideas
ive been doing lots of things like this lately =]

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