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
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Introductory Statistics (10th Edition)
- Premium control has a three machine process; the reliability ratings for the machines in the process are 0.7, 0.8, and 0.9. Each machine in the process is backed up by a redundant machine which has a reliability of 0.9. The increase in system reliability due to the redundancy is -----%?arrow_forwardAn auto shop wants to examine the proportion of customers that have to return after an appointment. Last year, an examination of 402 customers found that 22.4% had to return after an appointment. You instituted some changes at the auto shop this year, and found from a sample of 319 customers that 25.1% had to return after an appointment. You want to conduct an analysis to determine if there has been an increase in the proportion of customers that need return after an appointment since the past year, with a significance level of 10%. Using this information, what is the p of your analysis, accurate to three decimal places? 0.286 0.223 0.236arrow_forwardAn auto shop wants to examine the proportion of customers that have to return after an appointment. Last year, an examination of 375 customers found that 26.9% had to return after an appointment. You instituted some changes at the auto shop this year, and found from a sample of 430 customers that 33.9% had to return after an appointment. You want to conduct an analysis to determine if there has been an increase in the proportion of customers that need to return after an appointment since the past year, with a significance level of 1%. Using this information, what is the test statistic of your analysis? For the purposes of this analysis, use - Pcurrent year Plast Round any intermediate numbers to four decimal year. places and choose the closest choice to your answer. 2.575 1.03 2.15 1.64 3.30arrow_forward
- M3arrow_forward3. What percentage of College students have made at least one online purchase in the last three months? To answer this question, a market researcher surveyed 200 college students. Of those surveyed, 76 said that they had made at least one online purchase (a.) What is the parameter of interest in this study? (b.) Calculate the corresponding point estimate of the population proportarrow_forwardFör numbers 22 to 24 : the average length of time for the students to register for summer classes at a certain university has been 50 minutes with a variance of 100. A new registration procedure using computers is being tried. In a random sample of 30 students, the mean registration time was 42 minutes. Test the hypothesis that the average length of time for registration has been shortened due to the new system. 22. What is the value of the test statistic? A. -4.382 B. 5.014 C. 2.033 D. 1.584 23. At a 0.05 level of significance, what is the critical value? B. -1.645 C. -1.96 D. -1.699 A. -2.045 24. What ca u conclude about the new system of registration? A. There is enough evidence that the new system registration shortened the average length of time for students to register. B. There is insufficient evidence that the new system of registration shortened the average length of time for students to register.arrow_forward
- The dataset below was collected from a survey to determine whether CFT development in the island can be used as a strategy for the sustainable management and utilization of the fishery and aquatic resources in small islands. It shows the monthly income (in thousand pesos) estimated by 200 randomly selected fishers in Guimaras according to the type of fishers (i.e., the income source of fishers is solely fishing or they have alternative/supplemental livelihood such as island hopping services, sari-sari store ownership, fish value adding and/or vending, souvenir selling, carpentry, as construction worker, farming and tour guiding) and their perceived benefit from CFT development in the island. From this dataset and using = 0.05, is there a significant difference in estimated monthly income due tofisher type? How about due to the CFT perceived benefit? How about due to the interaction between fishertype and the perceived CFT benefit?a. Analyze manually and assume that the…arrow_forwardThe mango is considered the "king of fruits" in many parts of the world. Mangoes are generally harvested at the mature green stage and ripen up during the marketing process of transport, storage, and so on. During this process, about 30% of the fruit is wasted. Because of this, the impact of harvest stage and storage conditions on the postharvest quality are of interest. In this experiment, the fruit was harvested at 80, 95, or 110 days after the fruit setting (the transition from flower to fruit) and then stored at temperatures of 20°C, 30°C, or 40°C. For each harvest time and storage temperature, a random sample of mangoes was selected, and the time to ripening was measured. MacBook Air O Macmillan Learning What are the factors, the treatments, and the response variables? Take each item from the answer bank and place into the appropriate category. Factor(s) Harvest time Time to ripening Treatment(s) Response variable(s) Answer Bank Storage temperature All combinations of harvest time…arrow_forwardThe 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_forward
- An auto shop wants to examine the proportion of customers that have to return after an appointment. Last year, an examination of 350 customers found that 34.7% had to return after an appointment. You instituted some changes at the auto shop this year, and found from a sample of 375 customers that 41.6% had to return after an appointment. You want to conduct an analysis to determine if there has been a change in the proportion of customers that need to return after an appointment since the past year, with a significance level of 10%. Using this information, what is the SE (Pcurrent year Plast year) of your analysis? Round any intermediate numbers to four decimal places and choose the closest choice to your answer. 0.0361 0.0275 0.3827 0.0254 0.0149arrow_forwardA company studied the number of lost-time accidents occurring at its Brownsville, Texas, plant. Historical records show that 9% of the employees suffered lost-time accidents last year. Management believes that a special safety program will reduce such accidents to 4% during the current year: In addition, it estimates that 15% of employees who had lost-time accidents last year will experience a lost-time accident during the current year. a. What percentage of the employees will experience last-time accidents in both years (to 2 decimals)? 1.05 464 b. What percentage of the employees will suffer at least one lost-time accident over the two-year period (to 2 decimals)? 12.65arrow_forwardThe report “Undergraduate Students and Credit Cards in 2004: An Analysis of Usage Rates and Trends” (Nellie Mae, May 2005) estimated that 21% of undergraduates with credit cards pay them off each month and that the average outstanding balance on undergraduates’ credit cards is $2169. These estimates were based on an online survey that was sent to 1260 students. Responses were received from 132 of these students. Is it reasonable to generalize the reported estimates to the population of all undergraduate students? Address two possible sources of bias, and name the bias in your answer.arrow_forward
- Big Ideas Math A Bridge To Success Algebra 1: Stu...AlgebraISBN:9781680331141Author:HOUGHTON MIFFLIN HARCOURTPublisher:Houghton Mifflin Harcourt