The susceptibility of catfish to a certain chemical pollutant was determined by immersing individual fish in 2 liters of an emulsion containing the pollutant and measuring the survival time in minutes.9 The data in the following table give the common log of survival time (Y) and the common log of concentration (X) of the pollutant in parts per million for 18 fish.
a. Determine and draw the estimated straight line of F regressed on X on the accompanying scatter diagram. Comment on the fit.
b. Test for the significance of the straight-line regression. Interpret your result.
c. Determine 95% confidence intervals for the true mean survival time µY|X (where Y = 10Y) at values of X = 5, 4.5, and 4. ( = 4.5.) Interpret these intervals.

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Lo Logio Concentration Cx) gto Survival Fish Time (Y) 2.516 2.572 2.438 2.621 2.742 2.689 2.830 2.910 2.983 3.175 3.056 3.095 3.332 3.221 3.293 3.447 3.523 3.551 5.0 5.0 4.8 4.8 4.8 4.6 4.6 4.6 4.4 4.4 4.4 4.2 4.2 4.2 4.0 4.0 4.0 10 12 13 14 15 16 17 18 4 3.5 0 0 4 4.5 Logio concentration (X)