Spreading rate of spilled liquid. Refer to the Chemical Engineering Progress (Jan. 2005) study of the rate at which a spilled volatile liquid will spread across a surface, Exercise 11.31 (p. 566). Recall that the data on mass of the spill and elapsed time is saved in the LIQUIDSPILL file. Is there sufficient evidence (at a = .05) to indicate that the mass of the spill tends to diminish linearly as elapsed time increases? If so, give an interval estimate (with 95% confidence) of the decrease in spill mass for each minute of elapsed time.

Exercise 11.31

Spreading rate of spilled liquid. Refer to the Chemical Engineering Progress (Jan. 2005) study of the rate at which a spilled volatile liquid will spread across a surface, presented in Exercise 2.158 (p. 91). Recall that a DuPont Corp. engineer calculated the mass (in pounds) of a 50-gallon methanol spill after a period ranging from 0 to 60 minutes. Do the data shown in the accompanying table (saved in the LIQUIDSPILL file) indicate that the mass of the spill tends to diminish as time increases? If so, how much will the mass diminish each minute?

Exercise 2.158

Spreading rate of spilled liquid. A contract engineer at DuPont Corp. studied the rate at which a spilled volatile liquid will spread across a surface (Chemical Engineering Progress , Jan. 2005). Suppose that 50 gallons of methanol spills onto a level surface outdoors. The engineer uses derived empirical formulas (assuming a state of turbulence-free convection) to calculate the mass (in pounds) of the spill after a period ranging from 0 to 60 minutes. The calculated mass values are given in the table below and saved in the LIQUIDSPILL file. Is there evidence to indicate that the mass of the spill tends to diminish as time increases?