It is common practice in many countries to destroy (shred) refrigerators at the end of their useful lives. In this process material from insulating foam may be released into the atmosphere. The article “Release of Fluorocarbons from Insulation Foam in Home Appliances During Shredding” (J. of the Air and Waste Mgmt. Assoc., 2007: 1452–1460) gave the following data on foam density (g/L) for each of two refrigerators produced by four different manufacturers:
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Does it appear that true average foam density is not the same for all these manufacturers? Carry out an appropriate test of hypotheses by obtaining as much P-value information as possible, and summarize your analysis in an ANOVA table.
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Chapter 10 Solutions
Student Solutions Manual for Devore's Probability and Statistics for Engineering and the Sciences, 9th
- A study was conducted by the Department of Biological Sciences at Virginia Tech to determine if there is a significant difference in the density of organisms at two different stations located on Cedar Run, a secondary stream in the Roanoke River drainage basin. Sewage from a sewage treatment plant and overflow from the Federal Mogul Corporation settling pond enter the stream near its headwaters. The accompanying data give the density measurements, in number of organisms per square meter, at the two collecting stations. Can it be concluded, at the 0.05 level of significance, that the average densities at the two stations are equal? Assume that the observations come from normal populations with different variances. Click the icon to view the data on organisms per square meter. Let sample 1 be the station 1 data and let sample 2 be the station 2 data. State the null and alternative hypotheses. Hoi Hy-H2 = 0 H₁ H1 H2 0 (Type integers or decimals. Do not round.) Find the test statistic. The…arrow_forwardAn article in the Journal of Applied Polymer Science (Vol. 56, pp. 471–476, 1995) studied the effect of the mole ratio of sebacic acid on the intrinsic viscosity of copolyesters.- The data follows: Viscosity 0.45 0.2 0.34 0.58 0.7 0.57 0.55 0.44 Mole ratio 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 (a) Construct a scatter diagram of the data.arrow_forwardAn article in the Fire Safety Journal (“The Effect of Nozzle Design on the Stability and Performance of Turbulent Water Jets,” Vol. 4, August 1981) describes an experiment in which a shape factor was determined for several different nozzle designs at six levels of jet efflux velocity. Interest focused on potential differences between nozzle designs (blocks), with velocity considered as a nuisance variable. The data are shown below: Jet Efflux Velocity (m/s) Nozzle Design 11.73 14.37 16.59 20.43 23.46 28.74 1 0.78 0.80 0.81 0.75 0.77 0.78 2 0.85 0.85 0.92 0.86 0.81 0.83 3 0.93 0.92 0.95 0.89 0.89 0.83 4 1.14 0.97 0.98 0.88 0.86 0.83 5 0.97 0.86 0.78 0.76 0.76 0.75 1) Write the null hypothesis and the alternative hypothesis (for the factor). 2) Find the ANOVA table. (round to five decimal places). 3) What is your decision about the null hypothesis, consider ?. 4) If your decision in part (4) was reject , perform Tukey test to determine which pairwise means are…arrow_forward
- The article refered to in Exercise 1 also considered the effect of gypsum on the electric conductivity (in dS m) of soil. Two types of soil were each treated with three different amounts of gypsum, with two replicates for each soil-gypsum combination. The data are presented in the following table. Soil Type Gypsum (g/kg) Las Animas Madera 0.00 1.52 1.05 1.01 0.92 0.27 1.49 0.91 1.12 0.92 0.46 0.9 0.92 0.88 0.92 Is there convincing evidence of an interaction between the amount of gypsum and soil type? Can you conclude that the conductivity differs among the soil types? Can you conclude that the conductivity differs with the amount of gypsum added? C.arrow_forwardKingarrow_forward6arrow_forward
- Cell Phone Radiation Listed below are the measured radiation absorption rates (in W/kg) corresponding to these cell phones: iPhone 5S, BlackBerry Z30, Sanyo Vero, Optimus V, Droid Razr, Nokia N97, Samsung Vibrant, Sony Z750a, Kyocera Kona, LG G2, and Virgin Mobile Supreme. The data are from the Federal Communications Commission (FCC). The media often report about the dangers of cell phone radiation as a cause of cancer. The FCC has a standard that a cell phone absorption rate must be 1.6 W/kg or less. If you are planning to purchase a cell phone, are any of the measures of center the most important statistic? Is there another statistic that is most relevant? If so, which one?arrow_forwardSoil samples were collected at two areas surrounding an abandoned mine and analyzed for lead. At each area several samples were taken. The soil was extracted with acid, and the extract was analyzed using flame atomic absorption spectrometry. In Area A, Pb concentrations were 1.2, 1.0, 0.9, 1.4 mg/kg. In Area B, Pb concentrations were 0.7, 1.0, 0.5, 0.6, 0.4 mg/kg. Are these two areas significantly different from each other with Pb concentrations at 90% confidence level?arrow_forwardThe standard pH of a drinking water of MRWD is pH 7.0, the pH obtained from several water station are as follows: Station 1 7.8 Station 2 6.5 Station 3 5.8 Station 4 8.9 Station 5 6.8 Station 6 5.8 Station 7 9.0 Station 8 6.9 Test the hypothesis that the drinking water of the MRWD is safe for drinking.arrow_forward
- Fluid inclusions are microscopic volumes of fluid that are trapped in rock during rock formation. The article "Fluid Inclusion Study of Metamorphic Gold-Quartz Veins in Northwestern Nevada, U.S.A.: Characteristics of Tectonically Induced Fluid" (S. Cheong, Geosciences Journal, 2002:103-115) describes the geochemical properties of fluid inclusions in several different veins in northwest Nevada. The following table presents data on the maximum salinity (% NaCi by weight) of inclusions in several rock samples from several areas. Salinity Area Humboldt Range Santa Rosa Range 9.2 10.0 11.2 8.8 5.2 6.1 8.3 Ten Mile 7.9 6.7 9.5 7.3 10.4 7.0 Antelope Range Pine Forest Range 6.7 8.4 9.9 10.5 16.7 17.5 15.3 20.0 Can you conclude that the salinity differs among the areas?arrow_forwardThe article "Characteristics and Trends of River Discharge into Hudson, James, and Ungava Bays, 1964-2000" (S. Dery, M. Stieglitz, et al., Journal of Climate, 2005:2540-2557) presents measurements of discharge rate x (in kmlyr) andpeakflow y (in m/s) for 42 rivers that drain into the Hudson, James, and Ungava Bays. The data are shown in the following table: Discharge Peak Flow 94.24 4110.3 66.57 4961.7 59.79 10275.5 48.52 6616.9 40.00 7459.5 32.30 2784.4 31.20 3266.7 30.69 4368.7 26.65 1328.5 22.75 4437.6 21.20 1983.0 20.57 1320.1 19.77 1735.7 18.62 1944.1 17.96 3420.2 17.84 2655.3 16.06 3470.3 1561.6 14.69 11.63 869.8 11.19 936.8 11.08 1315.7 10.92 1727.1 9.94 768.1 7.86 483.3arrow_forwardThe article "Drying of Pulps in Sprouted Bed: Effect of Composition on Dryer Performance" (M. Medeiros, S. Rocha, et al., Drying Technology, 2002:865-881) presents measurements of pH, viscosity (in kg/m - s), density (in g/cm), and BRIX (in percent). The following MINITAB output presents the results of fitting the model pH = 6, +6, Viscosity + B, Density + ß, BRIX +€ The regression equation is pH - -1.79 + 0.000266 Viscosity + 9.82 Density - 0.300 BRIX Predictor Coef SE Coef Constant -1.7914 6.2339 -0.29 0.778 Viscosity 0.00026626 0.00011517 2.31 0.034 Density 9.8184 5.7173 1.72 0.105 BRIX -0.29982 0.099039 -3.03 0.008 S - 0.379578 R-Sq - 50.0% R-Sq(adj) - 40.6% Predicted Values for New Observations New Obs Fit SE Fit 95% CI 95% PI 3.0875 0.1351 (2.8010, 3.3740) (2.2333, 3.9416) (3.4207, 4.0496) (2.3255, 3.3896) 2 3.7351 0.1483 (2.8712, 4.5990) з 2.8576 0.2510 (1.8929, 3.8222) Values of Predictors for New Observations New Obs Viscosity Density BRIX 1000 1.05 19.0 1200 1.08 18.0 2000…arrow_forward
- Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill