Concept explainers
Salmonella in produce. Salmonella infection is the most common type of bacterial food-borne illness in the United States. How prevalent is salmonella in produce grown in the major agricultural region of Monterey, California? Researchers from the U S Department of Agnculture (USDA) conducted tests for salmonella in produce grown in the region and published their results in Applied and Environmental Microbiology (April 2011). In a sample of 252 cultures obtained from water used to Irrigate the region. 18 tested positive for salmonella In an independent sample of 476 cultures obtained from the region’s wildlife (e.g., birds), 20 tested positive for salmonella. Is this sufficient evidence for the USDA to state that the prevalence of salmonella in the region’s water differs from the prevalence of salmonella in the region’s wildlife? Use α = .01 to make your decision
Want to see the full answer?
Check out a sample textbook solutionChapter 8 Solutions
Statistics for Business and Economics (13th Edition)
- One variety of corn is genetically modified to produce chemicals for defense against predators. The standard corn contains the same standard genotype, but without genetic modification for the chemicals. The two types of corn are then planted in randomly placed adjacent plots across a single field. The amount of predators that are present when the corn has matured are then recorded. The data that was recorded of the predators present among each type are listed. Has genetic alterations decreased the amount of predators for the altered genotype? Normality tests for the populations of both contain a p value less than 0.05. The given alpha is 0.05 Modified Corn (20, 18, 26, 23, 17, 23, 22) Standard Corn (89, 64, 102, 96, 56, 77, 84, 59) use an F test to determine if the variance between the 2 lists are different. Based on this result, state the correct 2 sample parametric test to be used. State the null and alternative. Show calculations while rounding to two decimal points.What is the…arrow_forwardThe Specific Absorption Rate (SAR) for a cell phone measures the amount of radio frequency (RF) energy absorbed by the user’s body when using the handset. Every cell phone emits RF energy. Different phone models have different SAR measures. To receive certification from the Federal Communications Commission (FCC) for sale in the United States, the SAR level for a cell phone must be no more than 1.6 watts per kilogram. A random sample of 20 of the highest SAR level for a random selection of cell phone models as measured by the FCC was collected. Find a 96% confidence interval for the true (population) mean of the Specific Absorption Rates (SARs) for cell phones. Assume that the population standard deviation is σ = 0.337 and the sample mean is 1.024arrow_forwardFIV (feline immunodeficiency virus) attacks a cat's immune system causing FAIDS (feline acquired immunodeficiency syndrome). It is estimated that between 2 and 25 percent of the global domestic cat population is infected with the virus. FIV is primarily transmitted from cat to cat through biting. A one-step immunochromatographic (IC) test has been developed for the detection of FIV antibodies. It is estimated that 94.7% of cats with FIV test positive and 96.1% of cats without FIV test negative using this test. Assume that 5% of the local cat population is actually infected with FIV.Use this information to answer the following: (a) For a population of 100 000 cats:i. how many are estimated to be infected with FIV?ii. how many of the cats in (a)(i) will test positive? (b) Use your answers from (a) to help construct a 2 x 2 table of counts displaying the results for this sample. Complete the table. (c) Estimate the proportion of local cats that would test negative for FIV but…arrow_forward
- FIV (feline immunodeficiency virus) attacks a cat's immune system causing FAIDS (feline acquired immunodeficiency syndrome). It is estimated that between 2 and 25 percent of the global domestic cat population is infected with the virus. FIV is primarily transmitted from cat to cat through biting. A one-step immunochromatographic (IC) test has been developed for the detection of FIV antibodies. It is estimated that 94.7% of cats with FIV test positive and 96.1% of cats without FIV test negative using this test. Assume that 5% of the local cat population is actually infected with FIV. Use this information to answer the following: (a) For a population of 100 000 cats: (i) how many are estimated to be infected with FIV? (ii) how many of the cats in (a)(i) will test positive? (b) Use your answers from (a) to help construct a 2 × 2 table of counts displaying the results for this sample. Complete the table. Estimate the proportion of local cats that would test negative for FIV but actually be…arrow_forwardVermont maple sugar producers sponsored a testing program to determine the benefit of a potential new fertilizer regimen. A random sample of 27 maple trees in Vermont were chosen and treated with one of three levels of fertilizer suggested by the chemical producer. In this experimental setup, nine trees (three in each of three climatic zones) were treated with each fertilizer level and the amount of sap produced (in mL) by the trees in the subsequent season was measured. The results are presented in the following table. Southern Zone Central Zone Northern Zone 76.2 80.4 74.2 79.4 87.9 86.9 84.5 85.2 80.1 Low fertilizer Medium 87.0 95.1 93.0 98.2 94.7 96.2 88.4 90.4 922 fertilizer High 84.2 87.5 83.1 90.3 89.9 93.2 81.4 84.7 82.2 fertilizer Estimate the main effects of fertilizer levels and climatic zone, and their interactions. b. Construct an ANOVA table. You may give ranges for the P-values. Test the hypothesis that there is no interaction between fertilizer levels and climatic zone.…arrow_forwardInorganic phosphorous is a naturally occurring element in all plants and animals, with concentrations increasing progressively up the food chain (fruit < vegetables < cereaise nuts < corpse). Geochemical surveys take soil samples to determine phosphorous content (in ppm, parts per million). A high phosphorous content may or may not indicate an ancient burial site, food storage site, or even a garbage dump. Independent random samples from two regions gave the following phosphorous measurements (in ppm). Assume the distribution of phosphorous is mound-shaped and symmetric for these two regions. Region It x n, 15 857 1,551 1,230 875 1,080 2,330 1,850 1,860 2,340 1,080 910 1,130 1,450 1,260 1,010 Region III xi n 14 542 B06 1,230 1,770 790 960 1,650 860 890 640 1,180 1,160 1,050 1,020 A USE SALT (a) Use a caiculator with mean and standard deviation keys to verify that a and s (Round your answers to four decimal places.) ppm ppm ppm ppm (b) Let , be the population mean for x, and let be the…arrow_forward
- Inorganic phosphorous is a naturally occurring element in all plants and animals, with concentrations increasing progressively up the food chain (fruit < vegetables < cereals < nuts < corpse). Geochemical surveys take soil samples to determine phosphorous content (in ppm, parts per million). A high phosphorous content may or may not indicate an ancient burial site, food storage site, or even a garbage dump. Independent random samples from two regions gave the following phosphorous measurements (in ppm). Assume the distribution of phosphorous is mound-shaped and symmetric for these two regions Region I: x1; n1 = 15 855 1550 1230 875 1080 2330 1850 1860 2340 1080 910 1130 1450 1260 1010 Region II: x2; n2 = 14 540 810 790 1230 1770 960 1650 860 890 640 1180 1160 1050 1020 (a) Use a calculator with mean and standard deviation keys to verify that x1, S1, X2, and s2. (Round your answers to one decimal place.) X1 ppm S1 = ppm X2 = ppm S2 = ppm (b) Let µ1 be the population mean for x1 and let…arrow_forwardInorganic phosphorous is a naturally occurring element in all plants and animals, with concentrations increasing progressively up the food chain (fruit < vegetables < cereals < nuts < corpse). Geochemical surveys take soil samples to determine phosphorous content (in ppm, parts per million). A high phosphorous content may or may not indicate an ancient burial site, food storage site, or even a garbage dump. Independent random samples from two regions gave the following phosphorous measurements (in ppm). Assume the distribution of phosphorous is mound-shaped and symmetric for these two regions. Region I: x1; n1 = 15 853 1,549 1,230 875 1,080 2,330 1,850 1,860 2,340 1,080 910 1,130 1,450 1,260 1,010 Region II: x2; n2 = 14 538 808 790 1,230 1,770 960 1,650 860 890 640 1,180 1,160 1,050 1,020 (a) Use a calculator with mean and standard deviation keys to verify that x1, s1, x2, and s2. (Round your answers to four decimal places.) x1= ppm s1= ppm x2= ppm s2=…arrow_forwardInorganic phosphorous is a naturally occurring element in all plants and animals, with concentrations increasing progressively up the food chain (fruit < vegetables < cereals < nuts < corpse). Geochemical surveys take soil samples to determine phosphorous content (in ppm, parts per million). A high phosphorous content may or may not indicate an ancient burial site, food storage site, or even a garbage dump. Independent random samples from two regions gave the following phosphorous measurements (in ppm). Assume the distribution of phosphorous is mound-shaped and symmetric for these two regions Region I: x1; n1 = 15 855 1550 1230 875 1080 2330 1850 1860 2340 1080 910 1130 1450 1260 1010 Region II: x2; n2 = 14 540 810 790 1230 1770 960 1650 860 890 640 1180 1160 1050 1020 (a) Use a calculator with mean and standard deviation keys to verify that x1, s1, x2, and s2. (Round your answers to one decimal place.) x1 = ppm s1 = ppm x2 = ppm s2 = ppm (b)…arrow_forward
- Inorganic phosphorous is a naturally occurring element in all plants and animals, with concentrations increasing progressively up the food chain (fruit < vegetables < cereals < nuts < corpse). Geochemical surveys take soil samples to determine phosphorous content (in ppm, parts per million). A high phosphorous content may or may not indicate an ancient burial site, food storage site, or even a garbage dump. Independent random samples from two regions gave the following phosphorous measurements (in ppm). Assume the distribution of phosphorous is mound-shaped and symmetric for these two regions Region I: x1; n1 = 15 855 1550 1230 875 1080 2330 1850 1860 2340 1080 910 1130 1450 1260 1010 Region II: x2; n2 = 14 540 810 790 1230 1770 960 1650 860 890 640 1180 1160 1050 1020 (a) Use a calculator with mean and standard deviation keys to verify that x1, s1, x2, and s2. (Round your answers to one decimal place.) x1 = ppm s1 = ppm x2 = ppm s2 = ppm…arrow_forwardInorganic phosphorous is a naturally occurring element in all plants and animals, with concentrations increasing progressively up the food chain (fruit < vegetables < cereals < nuts < corpse). Geochemical surveys take soil samples to determine phosphorous content (in ppm, parts per million). A high phosphorous content may or may not indicate an ancient burial site, food storage site, or even a garbage dump. Independent random samples from two regions gave the following phosphorous measurements (in ppm). Assume the distribution of phosphorous is mound-shaped and symmetric for these two regions. REGION I:X1;N1=15 857 1,551 1,230 875 1,080 2,330 1,850 1,860 2,340 1,080 910 1,130 1,450 1,260 1,010 REGION II:X2;N2=14 538 812 790 1,230 1,770 960 1,650 860 890 640 1,180 1,160 1,050 1,020 (a) Use a calculator with mean and standard deviation keys to verify that x1, s1, x2, and s2. (Round your answers to four decimal places.) x1= ppm s1= ppm x2= ppm s2= ppm…arrow_forwardInorganic phosphorous is a naturally occurring element in all plants and animals, with concentrations increasing progressively up the food chain (fruit < vegetables < cereals < nuts < corpse). Geochemical surveys take soil samples to determine phosphorous content (in ppm, parts per million). A high phosphorous content may or may not indicate an ancient burial site, food storage site, or even a garbage dump. Independent random samples from two regions gave the following phosphorous measurements (in ppm). Assume the distribution of phosphorous is mound-shaped and symmetric for these two regions. Region I: x,; n, = 15 875 1,080 2,330 1,850 1,860 853 1,551 1,230 2,340 1,080 910 1,130 1,450 1,260 1,010 Region II: x,; n, = 14 540 808 790 1,230 1,770 960 1,650 860 890 640 1,180 1,160 1,050 | 1,020 In USE SALT (a) Use a calculator with mean and standard deviation keys to verify that x,, S,, x2, and s,. (Round your answers to four decimal places.) X1 ppm S. = ppm X2 ppm 52 ppm (b) Let u, be the…arrow_forward
- MATLAB: An Introduction with ApplicationsStatisticsISBN:9781119256830Author:Amos GilatPublisher:John Wiley & Sons IncProbability and Statistics for Engineering and th...StatisticsISBN:9781305251809Author:Jay L. DevorePublisher:Cengage LearningStatistics for The Behavioral Sciences (MindTap C...StatisticsISBN:9781305504912Author:Frederick J Gravetter, Larry B. WallnauPublisher:Cengage Learning
- Elementary Statistics: Picturing the World (7th E...StatisticsISBN:9780134683416Author:Ron Larson, Betsy FarberPublisher:PEARSONThe Basic Practice of StatisticsStatisticsISBN:9781319042578Author:David S. Moore, William I. Notz, Michael A. FlignerPublisher:W. H. FreemanIntroduction to the Practice of StatisticsStatisticsISBN:9781319013387Author:David S. Moore, George P. McCabe, Bruce A. CraigPublisher:W. H. Freeman