|
About 77631 results. 1294 free access solutions
| № |
Condition |
free/or 0.5$ |
| m102945 | Wolf packs tend to be large extended family groups that have a well-defi ned hunting territory. Wolves not in the pack are driven out of the territory or killed. In ecologically similar regions, is the size of an extended wolf pack related to size of hunting region? Using radio collars on wolves, the size of the hunting region can be estimated for a given pack of wolves. Let x represent the number of wolves in an extended pack and y represent the size of the hunting region in km2/1000. From Denali National Park we have the following data.
Reference: The Wolves of Denali by Mech, Adams, Meler, Burch, and Dale. University of Minnesota Press.
(a) Verify that Σx = 252. Σy = 59.86. Σx2 = 16,894. Σy2 = 787.0194. Σxv = 3527.87, and r ≈ 0.9405.
(b) Use a 1% level of significance to test the claim ρ > 0.
(c) Verify that Se ≈ 1.6453, a ≈ 5.8309.and b ≈ 0.l2l85.
(d) Find the predicted size of the hunting region for an extended pack of 42 wolves.
(e) Find an 85% confidence interval for your prediction of part (d).
(1) Use a 1% level of significance to test the claim that β > 0.
(g) Find a 95% confidence interval for and interpret its meaning in terms of territory size per wolf. |
buy |
| m102946 | Workers at a large toxic cleanup project are concerned that their white blood cell counts may have been reduced. Let x be a random variable that represents white blood cell count per cubic millimeter of whole blood in a healthy adult. Then ( ( 7500 and ( ( 1750 (Reference: Diagnostic Tests with Nursing Applications, S. Loeb).
A random sample of n = 50 workers from the toxic cleanup site were given a blood test that showed x̅ = 6820. What is the probability that, for healthy adults, x̅ will be this low or lower?
(a) How does the central limit theorem apply? Explain.
(b) Compute P(x̅ ( 6820).
(c) Interpretation Based on your answer to part (b), would you recommend that additional facts be obtained, or would you recommend that the workers concerns be dismissed? Explain. |
buy |
| m102947 | Write a brief but complete essay in which you describe the probability distributions you have studied so far. Which apply to discrete random variables? Which apply to continuous random variables? Under what conditions can the binomial distribution be approximated by the normal? by the Poisson? |
buy |
| m102948 | Yahoo Finance reported the beta value for Coca-Cola was .82 (Yahoo Finance website, June 30, 2016). Betas for individual stocks are determined by simple linear regression. The dependent variable is the total return for the stock, and the independent variable is the total return for the stock market, such as the return of the S&P 500. The slope of this regression equation is referred to as the stock s beta. Many financial analysts prefer to measure the risk of a stock by computing the stock s beta value.
The data contained in the DATAfile named CocaCola show the monthly percentage returns for the S&P 500 and the Coca-Cola Company for August 2015 to May 2016.
a. Develop a scatter diagram with the S&P % Return as the independent variable.
b. What does the scatter diagram developed in part (a) indicate about the relationship between the returns of the S&P 500 and those of the Coca-Cola Company?
c. Develop the least squares estimated regression equation.
d. Provide an interpretation for the slope of the estimated equation (that is, the beta).
e. Is your beta estimate close to .82? If not, why might your estimate be different? |
buy |
| m102949 | Yellowstone Park Medical Services (YPMS) provides emergency health care for park visitors. Such health care includes treatment for everything from indigestion and sunburn to more serious injuries. A recent issue of Yellowstone Today (National Park Service Publication) indicated that the average number of visitors treated each day by YPMS is 21.7. The estimated standard deviation is 4.2 (summer data). The distribution of numbers treated is approximately mound-shaped and symmetric.
(a) For a 10-day summer period, the following data show the number of visitors treated each day by YPMS:
Make a control chart for the daily number of visitors treated by YPMS, and plot the data on the control chart. Do the data indicate that the number of visitors treated by YPMS is "in control"? Explain your answer.
(b) For another 10-day summer period, the following data were obtained:
Make a control chart, and plot the data on the chart. Interpretation Do the data indicate that the number of visitors treated by YPMS is "in control" or "out of control"? Explain your answer. Identify all out-of-control signals by type (I, II, or III). If you were the park superintendent, do you think YPMS might need some (temporary) extra help? Explain. |
buy |
| m102950 | Yen, Lin, and Chiu (2013) compared the number of male and female people with an intelligence disability (ID) to the proportion of males and females in the general population. In their study, they reported that the number of males with an ID was 49,451 and the number of females with an ID was 45,935. The researchers identified that the proportion of males and females in the general population was 50.8% males and 49.2% females. Using these proportions to compute expected frequencies, conduct a chi-square goodness-of-fit test and decide whether to retain or reject the null hypothesis. |
buy |
| m102951 | You do not need a lot of money to invest in a mutual fund. However, if you decide to put some money into an investment, you are usually advised to leave it in for (at least) several years. Why? Because good years tend to cancel out bad years, giving you a better overall return with less risk. To see what we mean, let s use a 3-year moving average on the Calvert Social Balanced Fund (a socially responsible fund).
(a) Use a calculator with mean and standard deviation keys to verify that the mean annual return for all 11 years is approximately 9.45%, with standard deviation 9.57%.
(b) To compute a 3-year moving average for 1992, we take the data values for year 3 and the prior 2 years and average them. To compute a 3-year moving average for year 4, we take the data values for year 4 and the prior 2 years and average them. Verify that the following 3-year moving averages are correct.
(c) Use a calculator with mean and standard deviation keys to verify that for the 3-year moving average, the mean is 10.68% with sample standard deviation 4.53%.
(d) Interpretation Compare the results of parts (a) and (c). Suppose we take the point of view that risk is measured by standard deviation. Is the risk (standard deviation) of the 3-year moving average considerably smaller? This is an example of a general phenomenon that will be studied in more detail in Chapter 6. |
buy |
| m102952 | You don t need to be rich to buy a few shares in a mutual fund. The question is, "How reliable are mutual funds as investments?"That depends on the type of fund you buy. The following data are based on information taken from Morningstar, a mutual fund guide available in most libraries. A random sample of percentage annual returns for mutual funds holding stocks in aggressive-growth small companies is shown next.
Use a calculator to verify that s2 ( 348.43 for the sample of aggressive growth small company funds.
Another random sample of percentage annual returns for mutual funds holding value (i.e., market underpriced) stocks in large companies is shown next.
Use a calculator to verify that s2 ( 137.31 for value stocks in large companies.
Test the claim that the population variance for mutual funds holding aggressive-growth small stocks is larger than the population variance for mutual funds holding value stocks in large companies. Use a 5% level of signifi cance. How could your test conclusion relate to the question of reliability of returns for each type of mutual fund?
Please provide the following information.
(a) What is the level of signi ficance? State the null and alternate hypotheses.
(b) Find the value of the sample F statistic. What are the degrees of freedom?
What assumptions are you making about the original distribution?
(c) Find or estimate the P-value of the sample test statistic.
(d) Based on your answers in parts (a) to (c), will you reject |
buy |
| m102953 | You have two cards. One is red on both sides, and the other is red on one side and black on the other. After shuffling the cards behind your back, you select one of them at random and place it on your desk with your hand covering it. Upon lifting your hand, you observe that the face showing is red.
a. What is the probability that the other side is red?
b. Provide an intuitive explanation for the result in part (a). |
buy |
| m102954 | Young Professional magazine was developed for a target audience of recent college graduates who are in their first 10 years in a business/professional career. In its two years of publication, the magazine has been fairly successful. Now the publisher is interested in expanding the magazine s advertising base. Potential advertisers continually ask about the demographics and interests of subscribers to Young Professional. To collect this information, the magazine commissioned a survey to develop a profile of its subscribers. The survey results will be used to help the magazine choose articles of interest and provide advertisers with a profile of subscribers. As a new employee of the magazine, you have been asked to help analyze the survey results.
Some of the survey questions follow:
1. What is your age?
2. Are you: Male_________ Female___________
3. Do you plan to make any real estate purchases in the next two years? Yes______ No______
4. What is the approximate total value of financial investments, exclusive of your home, owned by you or members of your household?
5. How many stock/bond/mutual fund transactions have you made in the past year?
6. Do you have broadband access to the Internet at home? Yes______ No______
7. Please indicate your total household income last year.
8. Do you have children? Yes______ No______
The DATAfile named Professional contains the responses to these questions. Table 8.8 shows the portion of the file pertaining to the first fi |
buy |
| m102955 | Yuan and Maxwell (2005) investigated how the power of a study influences the decisions researchers make in an experiment. In their introduction concerning effect size, they stated that "the exact true effect size is generally unknown even after the experiment. But one can estimate the effect size ... [and] when the sample size is large the estimated effect size is near the true effect size" (Yuan & Maxwell, 2005, p. 141).
(a) Why is the "exact true effect size" generally unknown even after the experiment? Explain.
(b) How does increasing the sample size improve our estimate of effect size when we use estimated Cohen s d? |
buy |
|