A company would like to determine the relationship between: the time (in years) spent at the company and the employee’s hourly pay. The data for 5 employees are listed in the table below. Calculate and interpret the correlation coefficient r. Include a plot of the data in your discussion.
| years (X) | hourly pay (Y) |
|---|---|
| 5 | 25 |
| 3 | 20 |
| 4 | 21 |
| 10 | 35 |
| 15 | 38 |
a. Calculate the Pearson correlation coefficient for the data.
b. Use an appropriate 2-tailed hypothesis test (ɑ = .05) to determine whether this relationship is statistically significant.
c. Based on your calculations, what can we conclude about the relationship between the time spent at the company and hourly pay?
In: Math
1. Nutrient loss in food products is an important issue for food processing companies. We
would like to determine whether or not bread loses its vitamin C content over time.
a. Go to the Excel spreadsheet “Vitamin C in bread” that is posted with this assignment and
download it. There you will find results of an experiment conducted by a baking company.
The data show vitamin C content of 20 loaves of bread. Five of the loaves had vitamin C
measured the day of baking (day 0). Another five had vitamin C measured one day after
baking (day 1), and so forth for days 3 and 5.
b. Click Tools > Data Analysis and select the appropriate procedure for doing an analysis of
variance. I want to see a printout of the results obtained by using the Data Analysis Tool.
c. Interpret the results. Are there differences among the days in terms of vitamin C content?
What in the output tells you this?
|
Days after baking |
|||
|
0 days |
1 day |
3 days |
5 days |
|
46.2 |
37.5 |
23.1 |
10.0 |
|
54.3 |
27.0 |
13.9 |
13.5 |
|
42.9 |
44.1 |
24.3 |
15.8 |
|
37.0 |
31.0 |
29.4 |
8.9 |
|
38.1 |
36.7 |
34.1 |
25.3 |
2. Go the Excel spreadsheet “Trends in Vitamin C in bread” that is posted with this
assignment. There you will find the same data as in problem 1 but in a format that will allow
you to get a scatterplot and trendline.
a. Obtain the scatterplot and trendline (include the equation). I want to see a printout of this
analysis.
b. Use the equation in 2a to predict vitamin C content when day = 2. Include the answer on
your spreadsheet.
|
days |
vitamin C |
|
0 |
46.2 |
|
0 |
54.3 |
|
0 |
42.9 |
|
0 |
37.0 |
|
0 |
38.1 |
|
1 |
37.5 |
|
1 |
27.0 |
|
1 |
44.1 |
|
1 |
31.0 |
|
1 |
36.7 |
|
3 |
23.1 |
|
3 |
13.9 |
|
3 |
24.3 |
|
3 |
29.4 |
|
3 |
34.1 |
|
5 |
10.0 |
|
5 |
13.5 |
|
5 |
15.8 |
|
5 |
8.9 |
|
5 |
25.3 |
In: Math
A random sample of n = 64 observations has a mean x = 29. 1, and a standard deviation of s = 3.9. Find a 90 % confidence interval for the population mean.. A major department store chain is interested in estimating the average amount its credit card customers spent on their first visit to the chain's new store in the mall. Fifteen credit card accounts were randomly sampled and analyzed with the following results: = $50.50 and = 400. Find a 95% confidence interval for the average amount the credit card customers spent on their first visit to the chain's new store in the mall.
In: Math
Is there enough evidence in the data that population average price of diamond for color “E” is more than 1500?
Solve in R using the t test.
| Color | Price |
| D | 1302 |
| E | 1510 |
| G | 1510 |
| G | 1260 |
| D | 1641 |
| E | 1555 |
| F | 1427 |
| G | 1427 |
| H | 1126 |
| I | 1126 |
| F | 1468 |
| G | 1202 |
| E | 1327 |
| I | 1098 |
| E | 1693 |
| F | 1551 |
| G | 1410 |
| G | 1269 |
| H | 1316 |
| H | 1222 |
| E | 1738 |
| F | 1593 |
| G | 1447 |
| H | 1255 |
| F | 1635 |
| H | 1485 |
| F | 1420 |
| H | 1420 |
| F | 1911 |
| H | 1525 |
| F | 1956 |
| H | 1747 |
| I | 1572 |
| E | 2942 |
| G | 2532 |
| E | 3501 |
| E | 3501 |
| F | 3501 |
| F | 3293 |
| G | 3016 |
| F | 3567 |
| G | 3205 |
| D | 3490 |
| E | 3635 |
| F | 3635 |
| F | 3418 |
| D | 3921 |
| F | 3701 |
| F | 3480 |
| G | 3407 |
| E | 3767 |
| F | 4066 |
| E | 4138 |
| F | 3605 |
| G | 3529 |
| F | 3667 |
| I | 2892 |
| G | 3651 |
| G | 3773 |
| F | 4291 |
| E | 5845 |
| G | 4401 |
| G | 4759 |
| H | 4300 |
| F | 5510 |
| G | 5122 |
| H | 5122 |
| I | 3861 |
| F | 5881 |
| F | 5586 |
| F | 5193 |
| H | 5193 |
| F | 5263 |
| I | 5441 |
| I | 4948 |
| H | 5705 |
| F | 6805 |
| H | 6882 |
| H | 6709 |
| I | 6682 |
| E | 3501 |
| G | 3432 |
| F | 3851 |
| H | 3605 |
| E | 3900 |
| H | 3415 |
| H | 4291 |
| E | 6512 |
| E | 5800 |
| F | 6285 |
In: Math
Assume the age of death for all us burials(of persons over 5 years old) is approximately normally distributed and the sample mean is 68.84 and the standard deviation is 18.402926789.
Find the age at death such that 1.5% of US burials (of persons over 5 years old) were at least that old.
Find the probability that a burial randomly selected from all US burials (of persons over 5 years old) involved a person at least 30 years old.
Find the probability that a burial randomly selected from all US burials ( of persons over 5 years old) involved a person at most 85 years old.
In: Math
Which of the following are true about all normal distributions?
Check all that apply
A. They are symmetric.
B. They are all centered at zero.
C. They have one large tail.
D. They are categorically sharp.
I chose A and D but I still get errors . I dont know if my answer wrong or I have to add one more
In: Math
Probability Plot Problem:
Considering the following observations for X:
X = [19.0, 16.0, 14.0, 13.0, 12.0, 11.0, 10.5, 10, 9.7, 9.2, 8.7, 8.5]
a) Use Minitab to determine the type of probability distribution for X. Cut & paste the chart and briefly describe the reason for your answer.
b) Use the trendline in Excel to determine the equation f(x) for the observations. Cut & paste the chart with the trendline equation.
c) According to the above f(x), what is the predicted value of the next observation in the series?
_____________________________________________
In: Math
Assume that 15% of people are left-handed. If 6people are selected at random, find the probability of each outcome described below.
a) Find the probability that the first lefty is the sixth person chosen.
(Round to four decimal places as needed.)
b) Find the probability that there are some lefties among the 6 people.
(Round to four decimal places as needed.)
c) Find the probability that the first lefty is the fourth or fifth person.
(Round to four decimal places as needed.)
d) Find the probability that there are exactly 2 lefties in the group.
(Round to four decimal places as needed.)
e) Find the probability that there are at least 4 lefties in the group.
(Round to four decimal places as needed.)
f) Find the probability that there are no more than 2 lefties in the group.
(Round to four decimal places as needed.)
In: Math
The time required
to assemble an electronic component
is normally distributed, with a mean of
12 minutes and a standard deviation of
1.5 minutes. Find the probability that a
particular assembly takes:
a less than 14 minutes
b less than 10 minutes
c more than 14 minutes
d more than 8 minutes
e between 10 and 15 minutes.
In: Math
You submit your recommendations to your manager, and she tells you, “Thank you very much, but we have additional data for the Green Town Hopper: A 30% DOH results in a saving of 255 gallons per year. Please resubmit your recommendations taking this into account by tomorrow.” [hinT: You now have four data points on each graph, so try a general cubic instead: R 5 ax3 1 bx2 1 cx 1 d. Use a graph to estimate the optimal DOH
In: Math
88 Discuss the appropriateness of the frequentist practice of
keeping the level of a test constant irrespective of the sample
size.
89 What is the pre-testing problem? What are your views about this problem?
90 What is the post-selection problem? What are your views about
this problem?
In: Math
I want to know how to solve the following in excel. What is the x value and what is the Y value using the data table below?
Wal-Mart is the second largest retailer in the world. The data file (Wal-Mart Revenue 2004-2009.xlsx) is posted below the case study one file, and it holds monthly data on Wal-Mart’s revenue, along with several possibly related economic variables.
A. Develop a linear regression model to predict Wal-Mart revenue, using CPI as the only independent variable.
B. Develop a linear regression model to predict Wal-Mart revenue, using Personal Consumption as the only independent variable.
C. Develop a linear regression model to predict Wal-Mart revenue, using Retail Sales Index as the only independent variable.
D. Which of these three models is the best? Use R-square values, Significance F values, p-values and other appropriate criteria to explain your answer.
E. Generate a scatter plot, residual plot and normal probability plot for the best model in part (d) and comment on what you see.
| Date | Wal Mart Revenue | CPI | Personal Consumption | Retail Sales Index | December |
| 1/30/2004 | 12.131 | 554.9 | 7977730 | 281463 | 0 |
| 2/27/2004 | 13.628 | 557.9 | 8005878 | 282445 | 0 |
| 3/31/2004 | 16.722 | 561.5 | 8070480 | 319107 | 0 |
| 4/29/2004 | 13.98 | 563.2 | 8086579 | 315278 | 0 |
| 5/28/2004 | 14.388 | 566.4 | 8196516 | 328499 | 0 |
| 6/30/2004 | 18.111 | 568.2 | 8161271 | 321151 | 0 |
| 7/27/2004 | 13.764 | 567.5 | 8235349 | 328025 | 0 |
| 8/27/2004 | 14.296 | 567.6 | 8246121 | 326280 | 0 |
| 9/30/2004 | 17.169 | 568.7 | 8313670 | 313444 | 0 |
| 10/29/2004 | 13.915 | 571.9 | 8371605 | 319639 | 0 |
| 11/29/2004 | 15.739 | 572.2 | 8410820 | 324067 | 0 |
| 12/31/2004 | 26.177 | 570.1 | 8462026 | 386918 | 1 |
| 1/21/2005 | 13.17 | 571.2 | 8469443 | 293027 | 0 |
| 2/24/2005 | 15.139 | 574.5 | 8520687 | 294892 | 0 |
| 3/30/2005 | 18.683 | 579 | 8568959 | 338969 | 0 |
| 4/29/2005 | 14.829 | 582.9 | 8654352 | 335626 | 0 |
| 5/25/2005 | 15.697 | 582.4 | 8644646 | 345400 | 0 |
| 6/28/2005 | 20.23 | 582.6 | 8724753 | 351068 | 0 |
| 7/28/2005 | 15.26 | 585.2 | 8833907 | 351887 | 0 |
| 8/26/2005 | 15.709 | 588.2 | 8825450 | 355897 | 0 |
| 9/30/2005 | 18.618 | 595.4 | 8882536 | 333652 | 0 |
| 10/31/2005 | 15.397 | 596.7 | 8911627 | 336662 | 0 |
| 11/28/2005 | 17.384 | 592 | 8916377 | 344441 | 0 |
| 12/30/2005 | 27.92 | 609.4 | 8955472 | 406510 | 1 |
| 1/27/2006 | 14.555 | 573.9 | 9034368 | 322222 | 0 |
| 2/23/2006 | 16.87 | 595.2 | 9079246 | 318184 | 0 |
| 3/31/2006 | 16.639 | 598.6 | 9123848 | 366989 | 0 |
| 4/28/2006 | 17.2 | 603.5 | 9175181 | 357334 | 0 |
| 5/25/2006 | 16.901 | 606.5 | 9238576 | 380085 | 0 |
| 6/30/2006 | 21.47 | 607.8 | 9270505 | 373279 | 0 |
| 7/28/2006 | 16.542 | 609.6 | 9338876 | 368611 | 0 |
| 8/29/2006 | 16.98 | 610.9 | 9352650 | 382600 | 0 |
| 9/28/2006 | 20.091 | 607.9 | 9348494 | 352686 | 0 |
| 10/20/2006 | 16.583 | 604.6 | 9376027 | 354740 | 0 |
| 11/24/2006 | 18.761 | 603.6 | 9410758 | 363468 | 0 |
| 12/29/2006 | 28.795 | 604.5 | 9478531 | 424946 | 1 |
| 1/26/2007 | 16.1 | 606.3 | 9540335 | 332797 | 0 |
| 2/23/2007 | 17.984 | 594.6 | 9500318 | 327686 | 0 |
| 3/30/2007 | 18.939 | 599.3 | 9547774 | 376491 | 0 |
| 4/27/2007 | 22.47 | 613.3 | 9602393 | 366936 | 0 |
| 5/25/2007 | 19.201 | 642.8 | 9669845 | 389687 | 0 |
| 6/29/2007 | 23.77 | 623.9 | 9703817 | 382781 | 0 |
| 7/27/2007 | 18.942 | 625.6 | 9776564 | 378113 | 0 |
| 8/31/2007 | 19.38 | 626.9 | 9791220 | 392125 | 0 |
| 9/28/2007 | 22.491 | 623.9 | 9786798 | 362211 | 0 |
| 10/26/2007 | 18.983 | 619.9 | 9816093 | 364265 | 0 |
| 11/30/2007 | 21.161 | 620.6 | 9931068 | 372970 | 0 |
| 12/28/2007 | 31.245 | 642.5 | 9953178 | 434488 | 1 |
| 1/25/2008 | 19.923 | 623.4 | 10018937 | 342422 | 0 |
| 2/29/2008 | 21.512 | 622.3 | 10146599 | 344464 | 0 |
| 3/28/2008 | 19.023 | 626.9 | 10197093 | 339463 | 0 |
| 4/25/2008 | 20.178 | 651.2 | 10255207 | 388158 | 0 |
| 5/30/2008 | 21.9 | 636.1 | 10326976 | 378653 | 0 |
| 6/27/2008 | 21.24 | 638.7 | 10363123 | 397579 | 0 |
| 7/25/2008 | 22.1 | 640.2 | 10440525 | 394488 | 0 |
| 8/29/2008 | 20.981 | 641.9 | 10456119 | 389780 | 0 |
| 9/26/2008 | 20.419 | 643.2 | 10451414 | 403812 | 0 |
| 10/31/2008 | 20 | 641.2 | 10482584 | 373978 | 0 |
| 11/28/2008 | 21.022 | 637.9 | 10521902 | 381932 | 0 |
| 12/26/2008 | 32.85 | 656.9 | 10508628 | 443677 | 1 |
| 1/30/2009 | 19.784 | 637.8 | 10578596 | 350195 | 0 |
| 2/27/2009 | 20.962 | 639.7 | 10714428 | 353997 | 0 |
| 3/27/2009 | 22.951 | 638.9 | 10768153 | 356183 | 0 |
| 4/24/2009 | 22.062 | 643.7 | 10829987 | 351032 | 0 |
| 5/29/2009 | 20.856 | 648.1 | 10906349 | 354928 | 0 |
| 6/26/2009 | 23.700 | 649.4 | 10944809 | 395869 | 0 |
| 7/31/2009 | 24.413 | 651.4 | 11027165 | 389656 | 0 |
In: Math
describe the negative impact of using inappropriate measurements, including examples
In: Math
3. The average sale per customer at a department store is $120.00 with a standard deviation of $10.00.
According to the Empirical Rule, the percentage of sales between
$90.00 and $150.00 would be __________________
Using Chebyshev’s Theorem, the upper and lower limits for 75% of the data values =
_________to ___________.
c) If a customer spends $160.00, which of the following is correct?
a) It is an outlier because it’s more than 3 standard deviations below the mean.
b) It is an outlier because it’s more than 3 standard deviations above the mean.
c) It is not an outlier.
d) None of the above is correct.
In: Math
1. Sketch the area under the standard normal curve over the indicated interval and find the specified area. (Round your answer to four decimal places.)
The area to the right of z = 1.50 is _________
2. Sketch the area under the standard normal curve over the indicated interval and find the specified area. (Round your answer to four decimal places.)
The area to the left of z = −1.33 is ________
3. Sketch the area under the standard normal curve over the indicated interval and find the specified area. (Round your answer to four decimal places.)
The area between z = −2.25 and z = 1.41 is ________
4.Sketch the area under the standard normal curve over the indicated interval and find the specified area. (Round your answer to four decimal places.)
The area between z = −2.48 and z = −1.80 is ________
5. Assume that x has a normal distribution with the specified mean and standard deviation. Find the indicated probability. (Round your answer to four decimal places.)
μ = 5.0; σ = 2.4.
P(3 ≤ x ≤ 6) = ________
6. Assume that x has a normal distribution with the specified mean and standard deviation. Find the indicated probability. (Round your answer to four decimal places.)
μ = 109; σ = 12
P(x ≥ 90) = ________
In: Math