Refer to the Chemical Engineering Progress (Jan. 2005) study of the rate at which a spilled volatile liquid will spread across a surface, Recall that the data on mass of the spill and elapsed time is saved in the LIQUIDSPILL file.

Is there sufficient evidence (at α = .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.