Increasing hardness of polyester composites. Polyester resins reinforced with fiberglass are used to fabricate wall panels of restaurants. It is theorized that adding cement kiln dust (CKD) to the polyester composite will increase wall panel hardness. In a study published in Advances in Applied Physics (Vol. 2, 2014), hardness (Joules [J] per squared centimeters) was determined for three polyester composite mixtures that used a 40% CKD weight ratio. The hardness values were reported as 83, 84, and 79 J/cm2 Research has shown that the
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- 2. Three tensile tests were carried out on an aluminum bar. In each test, the strain was measured at the same values of stress. The results were Stress (MPa) 34.5 69.0 103.5 138.0 Strain (Test 1) 0.46 0.95 1.48 1.93 Strain (Test 2) 0.34 1.02 1.51 2.09 Strain (Test 3) 0.73 1.10 1.62 2.12 Where the units of strain are mm/m. Use linear regression to estimate the modulus of elasticity of the bar (modulus of elasticity = stress/strain). %3Darrow_forwardLichen has a high absorbance capacity for radiation fallout from nuclear accidents. Since lichen is a major source for Alaskan caribou, and caribou is major food source tor the Alaskan villagers, it is important to monitor the level of radioactivity in lichen. Researcher at the University of Alaska, Fairbanks, collected 9 lichen specimens and measured the amount in micro-curies per milliliter) of the radioactive element cesium-137 for each. Using the Minitab software, it was found that the mean and standard deviation for the 9 observations were X = 0.009027 аnd s = 0.004854 A) Give a point estimate for the mean amount of cesium in lichen specimens collected in Alaska. B) Give the t- value used in a small sample 95% confidence interval for the true mean amount of cesium in Alaskan lichen specimens. C) Form a 95% confidence interval for the true mean amount of cesium in Alaskan lichen specimens. D) Give a practical interpretation for the interval you obtained in part C. E) What…arrow_forwardThe compressive strength of an alloy fastener used in aircraft construction is being studied. Ten loads were selected over the range 2500–4300 psi, and a number of fasteners were tested at those loads. The numbers of fasteners failing at each load were recorded. The complete test data are shown in Table E11-14.arrow_forward
- The quality control engineer at Palmer Industries is interested in estimating the tensile strength of steel wire based on its outside diameter and the amount of molybdenum in the steel. As an experiment, she selected 25 pieces of wire, measured the outside diameters, and determined the molybdenum content. Then she measured the tensile strength of each piece. The results of the first four are recorded in the table. Tensile Strength Outside Diameter Amount of Molybdenum Place (PSI ) Y (mm) X1 (Units) X2 A 11 0.3 6 B 9 0.2 5 C 16 0.4 8 D 12 0.3 7 Using a statistical software package, the QC engineer determined the multiple regression equation to be Y’=-0.5+20X1+1X2. a) Based on the equation, what is the estimated tensile strength of a steel wire having an outside diameter of .35 mm and 6.4 units of molybdenum? b) Interpret the value of b1 in the equation.arrow_forwardSpecial dyes have been developed that only bind to DNA. The intensity of the color is directly related to the quantity of DNA present in the cell. A haploid cell would have a “low” amount of color, a cell in G1 would have a “medium” amount of color, and a cell in M phase would have a “high” amount of color. Is this sort of assessment quantitative, qualitative or semi-quantitative? Justify your reasoning.arrow_forwardAn engineer wants to compare the tensile strengths of steel bars that are produced using a conventional method and an experimental method. (The tensile strength of a metal is a measure of its ability to resist tearing when pulled lengthwise.) To do so, the engineer randomly selectoarrow_forward
- Shortleaf Pines. The ability to estimate the volume of a tree based on a simple measurement, such as the diameter of the tree, is important to the lumber industry, ecologists, and conservationists. Data on volume, in cubic feet, and diameter at breast height, in inches, for 70 shortleaf pines was reported in C. Bruce and F. X. Schumacher’s Forest Mensuration (New York: McGraw-Hill, 1935) and analyzed by A. C. Akinson in the article “Transforming Both Sides of a Tree” (The American Statistician, Vol. 48, pp. 307–312). The data are provided on the WeissStats site. a. obtain and interpret the standard error of the estimate. b. obtain a residual plot and a normal probability plot of the residuals. c. decide whether you can reasonably consider Assumptions 1–3 for regression inferences met by the two variables under consideration.arrow_forwardhelp thank you! Suppose a researcher is interested in the effectiveness in a new childhood exercise program implemented in a SRS of schools across a particular county. In order to test the hypothesis that the new program decreases BMI (Kg/m2), the researcher takes a SRS of children from schools where the program is employed and a SRS from schools that do not employ the program and compares the results. Assume the following table represents the SRSs of students and their BMIs. Student Intervention Group: Group 1BMI(kg/m2)Student Control Group: Group 2BMI(kg/m2)A18.6A21.6B18.2B18.9C19.5C19.4D18.9D22.6E24.1F23.6Assuming that all the necessary conditions are met (normality, independence, etc.) carry out the appropriate statistical test to determine if the new exercise program could decrease BMI (Kg/m2). Use an alpha level of 0.05 X=BMI mu_1 (?1): mean BMI of population from which Group 1 was sampled mu_2 (?2): mean BMI of population from which Group 2 was sampled What is the P-valule?…arrow_forward18.2 Well water having a total hardness of 300 mg / L as CaCO , is softened by split treatment . A zeolite bed takes 3/4 of the total flow and produces water at a hardness of 3 mg / L . as CaCO , One - fourth of flow is directly mixed with the softened water . The zeolite bed has 28.3 m² resin capacity . The water softening capacity of the resin is 62 kg / m³ total hardness as CaCO ,. Exhausted resin is regenerated by 98 percent pure NaCl solution . The salt consumption is three times the theoretical amount and used as 4 percent salt solution . Calculate ( a ) regeneration period if 950 m³ per day of water is passed through the softener , ( b ) the hardness of the fin ishod water , and ( c ) salt consumption per regeneration cyclearrow_forward
- Artificial hip joints consist of ball and socket. As the joint wears, the ball (head) becomes rough Investigators performed wear tests on metal artificial hip joints. Joints with several different diameters were tested. The Following table presents measurements of head roughness (in nanometers). Diameter Head Roughness 16 0.83 2.25 0.40 2.78 3.23 28 2.72 2.48 3.80 36 6.49 5.32 4.59 a. Because the design is unbalanced, check that the assumption of equal variances is by showing that the largest sample standard deviation is less than twice as large as the smallest one. b. Construct an ANOVA table. c. Can you conclude that the mean roughness varies with diameter? Use the a=0.01 level of significance.arrow_forwardHow wellmaterials conduct heat matters when designing houses, forexample. Conductivity is measured in terms of watts of heatpower transmitted per square meter of surface per degree Celsius of temperature difference on the two sides of the material.The National Institute of Standards and Technology (NIST)provides data on properties of materials. Here are 9 NISTmeasurements of the heat conductivity of a particular type offibrous-glass board: 0.0339 0.0337 0.0334 0.0334 0.03330.0333 0.0333 0.0332 0.0330 (a) We can consider this an SRS of all specimens of fibrousglass board of this type. Make a stemplot. Is there any sign ofmajor deviation from Normality? (b) Give a 95% confidence interval for the mean conductivity. (c) Is there significant evidence at the 5% level that themean conductivity of this type of fibrous-glass board is not0.0330?arrow_forwardAn experiment to compare the tension bond strength of polymer latex modified mortar (Portland cement mortar to which polymer latex emulsions have been added during mixing) to that of unmodified mortar resulted in x = 18.18 kgf/cm2 for the modified mortar (m = 42) and y = 16.86 kgf/cm for the unmodified mortar (n = 30). Let µ1 and Hz be the true average tension bond strengths for the modified and unmodified mortars, respectively. Assume that the bond strength distributions are both normal. (a) Assuming that o1 = 1.6 and o2 = 1.3, test Ho: µ1 - 42 = 0 versus H3: µ1 – 42 > 0 at level 0.01. Calculate the test statistic and determine the P-value. (Round your test statistic to two decimal places and your P-value to four decimal places.) z = P-value = State the conclusion in the problem context. Fail to reject Ho: The data does not suggest that the difference in average tension bond strengths exceeds from 0. o Reject Ho: The data does not suggest that the difference in average tension bond…arrow_forward
- Holt Mcdougal Larson Pre-algebra: Student Edition...AlgebraISBN:9780547587776Author:HOLT MCDOUGALPublisher:HOLT MCDOUGALAlgebra & Trigonometry with Analytic GeometryAlgebraISBN:9781133382119Author:SwokowskiPublisher:CengageAlgebra: Structure And Method, Book 1AlgebraISBN:9780395977224Author:Richard G. Brown, Mary P. Dolciani, Robert H. Sorgenfrey, William L. ColePublisher:McDougal Littell