Preliminary data analyses indicate that you can reasonably apply the z-interval procedure (Procedure 8.1 on page 339) in Exercises 8.69–8.74.
8.69 Venture-Capital Investments. Data on investments in the high-tech industry by venture capitalists are compiled by VentureOneCorporation and published in America’s Network Telecom Investor Supplement. A random sample of 18 venture-capital investments in the fiber optics business sector yielded the following data, in millions of dollars.
Determine and interpret a 95% confidence interval for the mean amount, μ, of all venture-capital investments in the fiber optics business sector. Assume that the population standard deviation is $2.04 million. (Note: The sum of the data is $113.97 million.)
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Introductory Statistics (10th Edition)
- In Exercises 13–20, determine whether the data are from a discrete or continuous data set. Texting Fatalities The Insurance Institute for Highway Safety collects data consisting of the numbers of motor vehicle fatalities caused by driving while texting.arrow_forwardThe accompanying table shows, for a random sample of 20 long-term-growth mutual funds, percentage return over a period of 12 months and total assets (in millions of dollars).Return Assets Return Assets Return Assets29.3 300 16.0 421 12.9 7527.6 70 15.5 99 11.3 61023.7 3,004 15.2 756 9.9 26422.3 161 15.0 730 7.9 2722.0 827 14.4 436 6.7 7119.6 295 14.0 143 3.3 71917.6 29 13.7 117a. Calculate the Spearman rank correlation coefficient.b. Carry out a nonparametric test of the null hypothesis of no association in the population against a two-sided alternative.c. Discuss the advantages of a nonparametric test for these data.arrow_forwardFind the technique for gathering data in the study below.An analysis of a sample of 31,000 patients from New York hospitals suggests that the poor and the elderly sue for malpractice at one-fifth the rate of wealthier patients (Journal of the Medical Association).arrow_forward
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- The table to the right represents the annual percentage of smartphones sold in a certain region in 2011, 2012, and 2013 (projected). a. What conclusions can you reach about the market for smartphones in 2011, 2012, and 2013? b. What differences are there in the market for smartphones in 2011, 2012, and 2013? a. Select all that apply. A. Type 6 had the smallest or close to the smallest percentage of smartphones sold in all three years. B. Type 3 had the second largest percentage of smartphones sold in all three years. C. Type 1 had the largest percentage of smartphones sold in all three years. D. Type 5 had the smallest or close to the smallest percentage of smartphones sold in all three years. E. Type 2 had the second largest percentage of smartphones sold in all three years. Туре Type 1 Type 2 Type 3 Type 4 Type 5 Type 6 2011 44% 21% 21% 10% 1% 3% 2012 69% 16% 4% 6% 3% 2% 2013 63% 17% 1% 3% 13% 3%arrow_forwardIn order to estimate attendance at a music festival, management counts the number of people entering the admissions gate in a 30- minute sample time. Management assumes that there is a steady stream of people entering the festival for the 10 hours that the admissions gate is open. At a particular music festival, 2,250 people were counted entering the gate in a 30- minute sample time. What was the estimated attendance at this festival?arrow_forwardThe table below shows the number of accidents, fatalities, hours flown, and miles flown for a country's airlines with scheduled service in selected years. Complete parts (a) and (b) below. Year Accidents Fatalities Hours Flown (millions) 16.1 Miles flown (billions) 6.7 2002 44 84 2008 28 21 18.7 7.9 2012 25 1 17.4 7.7 a. Compute the accident rate per million flight hours in 2002 and 2012. By this measure, has general aviation become safer? Select the correct choice below and fill in the answer boxes to complete your choice. (Round to the nearest tenth as needed.) accidents per million flight hours, is higher than the accident rate in 2012. OA. General aviation has become safer because the accident rate in 2002. accidents per million fight hours. accidents per million flight hours, is lower than the accident rate in 2012, B. General aviation has not become safer because the accident rate in 2002. accidents per million flight hours.arrow_forward
- Deaths from Motor Vehicle Crashes Listed below are the numbers of deaths in the United States resulting from motor vehicle crashes. Use the best model to find the projected number of such deaths for the year 2020.arrow_forwardIs there a difference in profit in the first quarter compared to the second quarter for investor’s portfolios? Each participant’s investment portfolio was evaluated in the first and second quarters to see if there was a difference. Which test should be conducted? Calculate the results, write up the results, and interpret what the results mean. The data set is below: First Second 17 19 18 20 19 20 20 22 21 24 22 21 23 28 24 26 14 20arrow_forwardA large manufacturing company producing air conditioner compressor believes the number of units of air conditioner sold is related to atmospheric temperature. An R&D officer conducted a study and gathered the following data: 3. Day Sale Temperature (Fahrenheit) 63 (in thousands) 1.52 1 2 70 1.68 3 73 1.8 4 75 2.05 80 2.36 6. 82 2.25 7 85 2.68 8 88 2.9 9. 90 3.14 3.06 3.24 10 91 11 92 12 75 1.92 13 98 3.4 14 100 3.28 Construct an estimated regression line between temperature and number of units sold. а) b) Does the model in part (a) confirm that contribution of temperature to number of units of air conditioner sold? Test using a 0.05. Find the coefficient of correlation. What does the value imply about the relationship of the two variables? c) If the temperature soared to 120 Fahrenheit, can you predict the number of units of air conditioner sold? Explain d)arrow_forward
- Big Ideas Math A Bridge To Success Algebra 1: Stu...AlgebraISBN:9781680331141Author:HOUGHTON MIFFLIN HARCOURTPublisher:Houghton Mifflin Harcourt