The article "Optimization of Medium Composition for Lipase Production by Candida rugosa NCIM 3462 Using Response Surface Methodology" (A. Ragendran and V. Thangavelu, Can J. Microbiol, 2007:643-655) describes a series of experiments in which lipase was produced from a bacterial culture. In each experiment, the rate of lipase production (in umol per ml enzyme per minute) and the cell mass (in g/L) were measured. The results are presented in the following table. Cell mass (x) Lipase (y) 4.50 2.06 4.68 2.10 5.40 3.15 5.45 4.10 4.20 2.20 4.12 3.20 4.00 2.85 4.50 2.10 4.41 3.98 4.72 2.75 3.41 2.80 4.80 4.60 3.60 2.50 4.95 4.10 3.25 2.15 4.40 4.40 3.65 2.20 4.23 2.30 4.10 2.40 5.03 4.75 3.15 3.90 4.19 4.40 3.92 3.20 3.50 2.10 4.15 3.75 4.30 3.15 4.90 5.10 5.23 5.04 5.40 4.96 4.85 5.00 5.10 4.92 4.94 4.98 a. Compute the least-squares line for predicting lipase production from cell mass. Compute 95% confidence intervals for B, and B,- c. In two experiments, the cell masses differed by 1.5 g/L. By how much do you estimate that their lipase productions will differ? d. Find a 95% confidence interval for the mean lipase production when the cell mass is 5.0 g/L. Can you conclude that the mean lipase production when the cell mass is 5.0 g/L is less than 4.4? Explain.

The article "Factorial Experiments in the Optimization of Alkaline Wastewater Pretreatment" (M. Prisciandaro, A. Del Borghi, and F. Veglio, Industrial Engineering and Chemistry Research, 2002:5034-5041) presents the results of an experiment to investigate the effects of the concentrations of sulfuric acid (H,So,) and calcium chloride (CaCl,) on the amount of black mud precipitate in the treatment of alkaline wastewater. There were three levels of each concentration, and two replicates of the experiment were made at each combination of levels. The results are presented in the following table (all measurements are in units of kg/m). H;5O, CaCl, 15 Precipitate 100.2 110 98.2 110 30 175.8 216.5 176.2 110 45 206.0 123 15 110.5 105.5 123 30 45 184.7 189.0 123 234.0 222.0 136 15 106.5 107.0 136 30 1817 189.0 136 45 211.8 201.3 a Construct an ANOVA table. You may give ranges for the P-values. b. Is the additive model plausible? Explain. c. Can you concude that H,S0, concentration affects the…

The vulnerability of inshore environments to contamination due to urban and industrial expansion in Mombasa is discussed in the paper €œMetals, Petroleum Hydrocarbons and Organo-chlorines in Inshore Sediments and Waters on Mombasa, Kenya€ [Marine Pollution Bulletin (1997) 34: 570€“ 577]. A geochemical and oceanographic survey of the inshore waters of Mombasa, Kenya, was undertaken during the period from September 1995 to January 1996. In the survey, suspended particulate matter and sediment were collected from 48 stations within Mombasa€™s ­estuarine creeks. The concentrations of major oxides and 13 trace elements were determined for a varying number of cores at each of the stations. In particular, the lead concentrations in suspended particulate matter (mg kg-1 dry weight) were determined at 37 stations. The researchers were ­interested in determining whether the average lead concentration was greater than 30 mg kg-1 dry weight. The data are given in the following table along with…

Seedlings of understory trees in mature tropical rainforests must survive and grow using inter- mittent flecks of sunlight. How does the length of exposure to these flecks of sunlight (fleck duration) affect growth? Leakey et al. (2005) experimentally irradiated seedlings of the Southeast Asian rainforest tree Shorea leprosula with flecks of light of varying duration while maintaining the same total irradiance to all the seedlings. Their data for 21 seedlings are listed in the following table.  i. What is the rate of change in relative growth rate per minute of fleck duration? provide a standard error for your estimate. ii. using these data, test the hypothesis that fleck duration affects seedling growth rate. iii. Calculate a 99% confidence interval for the slope of the population regression.

The decline of salmon fisheries along the Columbia River in Oregon has caused great concern among commercial and recreational fishermen. The paper 'Feeding of Predaceous Fishes on Out-Migrating Juvenile Salmonids in John Day Reservoir, Columbia River' (Trans. Amer. Fisheries Soc. (1991: 405-420) gave the accompanying data on y = maximum size of salmonids consumed by a northern squaw fish (the most abundant salmonid predator) and x = squawfish length, both in mm. Here is the computer software printout of the summary: Coefficients:                         Estimate     Std. Error     t value     Pr(> |t|)   (Intercept)   −89.010     16.703     −5.329     0.000   Length   0.705     0.046     15.293     0.000   Using this information, give the equation of the least squares regression line.

The article "Oxidation State and Activities of Chromium Oxides in Cao-SiO,-CrO, Slag System" (Y. Xiao, L. Holappa, and M. Reuter, Metallurgical and Materials Transactions B, 2002:595-603) presents the amount x (in mole percent) and activity coefficient y of CrO,5 for several specimens. The data, extracted from a larger table, are presented in the following table. х У 2.6 10.20 5.03 19.9 8.84 0.8 6.62 5.3 2.89 20.3 2.31 39.4 7.13 5.8 3.40 29.4 5.57 2.2 7.23 5.5 2.12 33.1 1.67 44.2 5.33 13.1 16.70 0.6 9.75 2.2 2.74 16.9 2.58 35.5 1.50 48.0 Compute the least-squares line for predicting y from x. b. Plot the residuals versus the fitted values. Compute the least-squares line for predicting y from 1/x. d. Plot the residuals versus the fitted values. C. Using the better fitting line, find a 95% confidence interval for the mean value of y when x= 5.0.

The article “Bioremediation of Soil Contaminated Crude Oil by Agaricomycetes” (Mohammad-Sichani, Assadi, et al., Journal of Environmental Health and Engineering, 2017, online) describes an experiment to determine the effectiveness of mushroom compost in removing petroleum contaminants from soil. Out of 150 seeds planted in soil containing 3% mushroom compost by weight, 74 germinated. Out of 150 seeds planted in soil containing 5% mushroom compost by weight, 86 germinated. Find a 95% confidence interval for the difference between the proportions of seeds that germinate.

During the spring of 1999, many fuel storage facilities in Serbia were destroyed by bombing. As a result, significant quantities of oil products were spilled and burned,resulting in soil pollution. The article “Mobility of Heavy Metals Originating from Bombing of Industrial Sites” (B. Škrbić, J. Novaković, and N. Miljević, Journal of Environmental Science and Health, 2002:7–16) reports measurements of heavy metal concentrations at several industrial sites in June 1999, just after the bombing, and again in March of 2000. At the Smederevo site, on the banks of the Danube River, eight soil specimens taken in 1999 had an average lead concentration (in mg/kg) of 10.7 with a standard deviation of 3.3. Four specimens taken in 2000 had an average lead concentration of 33.8 with a standard deviation of 0.50. Find a 95% confidence interval for the increase in lead concentration between June 1999 and March 2000.

sto ave 12.72 (M4) The authors of the paper "Serum Zinc Levels of Cord Blood: Relation to Birth Weight and Gestational Period" (Journal of Trace Elements in Medicine and Biology [2015]: 180-183) car- ried out a study of zinc levels of low-birth-weight babies and normal-birth-weight babies. For a sample of 50 low- birth-weight babies, the sample mean zinc level was 17.00 and the standard error was 0.43. For a sample of 73 normal-birth-weight babies, the sample mean zinc level was 18.16 and the standard error was 0.32. Explain why the two standard errors are not the same.