In building a model to study automobile fuel consumption, Biggs and Akcelik (Journal of Transportation Engineering, 113, no. 1, January 1987, pp. 101-106) begin by looking at the relationship between idle fuel consumption and engine capacity. Suppose the data are as presented in the table.

Idle fuel consumption (milliliters per second) …………………Engine size (liters)

0.18 ………………………………………………………………………………………….1.2

0.21 ………………………………………………………………………………………….1.2

0.17 ………………………………………………………………………………………….1.2

031 …………………………………………………………………………………………..1.8

0.34 ………………………………………………………………………………………….1.8

0.29 ………………………………………………………………………………………….1.8

0.42 ………………………………………………………………………………………….2.5

0.39 ………………………………………………………………………………………….2.5

0.45 ………………………………………………………………………………………….2.5

0.52 ………………………………………………………………………………………….3.4

0.61 ………………………………………………………………………………………….3.4

0.44 ………………………………………………………………………………………….3.4

0.62 ………………………………………………………………………………………….4.2

0.65 ………………………………………………………………………………………….4.2

0.59 ………………………………………………………………………………………….4.2

For a population of automobiles with engine size 2.5 liters, estimate the average idle fuel consumption, with a bound on the error of estimation.