A credit score is used by credit agencies (such as mortgage companies and banks) to assess the creditworthiness of individuals. Values range from 300 to 850, with a credit score over 700 considered to be a quality credit risk.According to a survey, the mean credit score is 706.3. A credit analyst wondered whether high-income individuals (incomes in excess of $100,000 per year) had higher credit scores. He obtained a random sample of 45 high-incomeindividuals and found the sample mean credit score to be 725.6 with a standard deviation of 81.6. Conduct the appropriate test to determine if high-income individuals have higher credit scores at the α = 0.05 level of significance.State the null and alternative hypotheses.Ho: μH₁:μ(Type integers or decimals. Do not round.)

Answered: A credit score is used by credit…

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

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A research poll included 1762 randomly selected adults who were asked whether "global warming is a problem that requires immediate government action." Results showed that 975 of those surveyed indicated that immediate government action is required. A news reporter wants to determine whether these survey results constitute strong evidence that the majority (more than 50%) of people believe that immediate government action is required. Complete parts (a) through (c) below. a. What is the best estimate of the proportion of adults who believe that immediate government action is required? The best estimate is ☐ (Round to three decimal places as needed.)
The price of a share of stock divided by the company's estimated future earnings per share is called the P/E ratio. High P/E ratios usually indicate "growth" stocks, or maybe stocks that are simply overpriced. Low P/E ratios indicate "value" stocks or bargain stocks. A random sample of 51 of the largest companies in the United States gave the following P/E ratiost. 9 20 11 35 19 13 15 21 29 53 16 26 21 14 21 27 10 12 47 14 40 18 60 72 33 14 8 49 5 16 8 19 12 31 67 51 26 18 17 20 19 13 25 23 27 44 20 27 19 18 32 (a) Use a calculator with mean and sample standard deviation keys to find the sample mean x and sample standard deviation s. (Round your answers to one decimal place.) (b) Find a 90% confidence interval for the P/E population mean u of all large U.S. companies. (Round your answers to one decimal place.) lower limit upper limit (c) Find a 99% confidence interval for the P/E population mean u of all large U.S. companies. (Round your answers to one decimal place.) lower limit upper…
Forbes magazine published data on the best small firms in 2012. These were firms that had been publicly traded for at least a year, have a stock price of at least $5 per share, and have reported annual revenue between $5 million and $1 billion. The table below shows the ages of the corporate CEOS for a random sample of these firms. 48 58 51 61 56 59 74 63 53 50 59 60 60 57 46 63 57 55 47 55 57 43 61 62 49 67 55 67 55 49 Use this sample data to construct a 90% confidence interval for the mean age of CEO's for these top small firms. Use the Student's t-distribution (a) what is the lower bound for 90% confidence interval for the mean age of CEO's? (Round to 3decimal places) UESTION 32 (b) What is the upper bound (Round to 3 decimla places)
A political scientist claims that 38% of first-year college students characterize themselves as being “moderate” or “middle of the road” as far as their political affiliation is concerned. Believing this claimed value is too high, you survey a random sample of 400 first-year college students and find that 120 characterize themselves as being “moderate” or “middle of the road.” Based on this information, what will the test statistic be? Choose the answer below that is closest to what you calculate, and try not to do a lot of rounding until you get to the very end of your calculations. 1. -0.3 2. -1.2 3. -2.6 4. -3.3 5. None of the other answer options are correct because the test statistic should be positive, not negative.
Foxbees magazine published data on the best small firms in 2012. These publicly traded firms have a stock price of at least $5 per share and have reported annual revenue between $5 million and $1 billion. The data below shows the ages of the corporate CEOS for a random sample of these firms. 49 67 59 48 45 49 39 44 37 38 48 38 43 48 62 74 70 58 58 40 74 35 36 54 38 45 54 55 64 75 69 36 55 72 69 60 40 64 39 59 74 52 40 49 38 38 74 50 55 50 R vector Copy to clipboard a) What is the mean of the sample? (Round to 4 decimal places) b) What is the standard deviation of the sample mean or the standard error? (Round to 4 decimal places) c) What is the sample size? (Round to whole number)
The General Social Survey is an annual survey given to a random selection of about 1500 adults in the United States. Among the many questions asked are "What is the highest level of education you've completed?" and "If you're employed full-time, how many hours do you spend working at your job during a typical week?" In a recent year, 1116 respondents answered both questions. The summary statistics are given in the chart below. (The sample data consist of the times, in hours per week, that were given by the respondents.) Sample Sample Sample Groups size mean variance Less than 281 41.6 115.8 h.s. High school 260 43.3 96.3 Bachelor's 294 42.5 100.5 Graduate 281 44.2 108.2 Send data to Excel Based on these summary statistics, we perform a one-way, independent-samples ANOVA test to determine if there is a difference in the mean hours worked in a typical week among the four populations of workers. (a) The results of this ANOVA are given in the incomplete ANOVA table below. Complete the…
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International experience around the world is important in our culture of globalization. According to NAFSA, 54.5% of all American students traveling abroad went to Europe in the 2014-2015 academic year. To determine if there is shift in the proportion of students traveling to Europe, suppose a random sample of 300 students who had studied abroad was taken for the 2015-2016 school year. One-hundred sixty of the students traveled to Europe. a. Conduct a test to determine if the proportion of students traveling to Europe has changed. Be sure to provide a complete write-up. b. Based on the hypothesis test, would you expect 0.545 to be in confidence interval for the proportion? Explain without constructing the interval.
The mean birthweight of an infant is thought to be associated with the smoking status of the mother during the first trimester of the pregnancy. Consider the following data from mothers divided into four categories according to smoking habits, and the corresponding birthweights of their children. Group 1: Mother is a non smoker (NON): 7.5, 6.2, 6.9, 7.4, 9.2, 8.3, 7.6 Group 2: Mother is an ex-smoker (EX): 5.8, 7.3, 8.2, 7.1, 7.8 Group 3: Mother is a current smoker, smokes less than 1 pack per day (CUR < 1) 5.9, 6.2, 5.8, 4.7, 8.3, 7.2, 6.2 Group 4: Mother is a current smoker, smokes more than or equal to 1 pack per day (Cur ≥ 1) 6.2, 6.8, 5.7, 4.9, 6.2, 7.1, 5.8, 5.4 Using Stata test whether or not the mean birthweights are equal across all four groups at the alpha = 0.05 level. What are your null and alternative hypothesis? Ο HO: μ_1== μ_2 HA: μ_1=\= μ_2 O HO: μ_i== u_j for all i and j HA: μ_i=\= μ_j for all i and j O HO: μ_i == μ_j for all i and j HA: μ_i=\= μ_j for at least one i,j…
The Wall Street Journal Corporate Perceptions Study 2011 surveyed readers and asked how each rated the quality of management and the reputation of the company for over 250 worldwide corporations. Both the quality of management and the reputation of the company were rated on an excellent, good, and fair categorical scale. Assume the sample data for 200 respondents below applies to this study. Quality of Management Reputation of Company Excellent Good Fair Excellent 40 25 5 Good 35 28 10 Fair 25 17 15 (a) Use a 0.05 level of significance and test for independence of the quality of management and the reputation of the company. State the null and alternative hypotheses. H0: Quality of management is not independent of the reputation of the company.Ha: Quality of management is independent of the reputation of the company. H0: Quality of management is independent of the reputation of the company.Ha: Quality of management is not independent of the…
Find the mean, median, and mode for a random sample of eight U.S. corporations with the following percentage changes in earnings per share in the current year compared with the previous year: 0% 0% 8.1% 13.6% 19.4% 20.7% 10.0% 14.2%

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