The efficiency for a steel specimen immersed in a phosphating tank is the weight of the phosphate coating divided by the metal loss (both in mg/ft2). An article gave the accompanying data on tank temperature (x) and efficiency ratio (y). Temp. 173 175 176 177 177 178 179 180 Ratio 0.74 1.41 1.52 1.05 1.09 1.18 0.98 1.82 Temp. 183 183 183 183 183 184 184 185 Ratio 1.37 1.68 1.63 2.07 2.07 0.78 1.39 0.84 Temp. 185 185 185 187 187 188 189 191 Ratio 1.83 1.98 2.74 1.43 2.56 2.90 1.77 3.10   (a) Determine the equation of the estimated regression line. (Round all numerical values to four decimal places.) y =  0.0890−14.7594x       (b) Calculate a point estimate for true average efficiency ratio when tank temperature is 185. (Round your answer to four decimal places.)   (c) Calculate the values of the residuals from the least squares line for the four observations for which temperature is 185. (Round your answers to two decimal places.) (185, 0.84)(185, 1.83)(185, 1.98)(185, 2.74)

3 The mass of a uniform sphere varies directly with the cube of its radius. A certain sphere has radius 3cm and mass 113.1 g. Find the mass of another sphere with radius 5 cm.

Water is flowing into a tub for washing clothes. The table shows the rate at which the water flows, in gallons per minute. The tub initially had five gallons of water in it before the faucet was turned on. t, in minutes 0 0.5 1 1.5 2 2.5 3 3.5 Flow rate, in 0.5 1 1.2 1.4 1.7 2 gal/min 2.1 3 Use the information in this problem to determine the amount of water in the tub after the first 3 minutes have passed. a) Calculate the amount of water in the tub using left approximating rectangles. b) Calculate the amount of water in the tub using right approximating rectangles. c) Use the two answers above to determine the most accurate answer you can.