Does everything increase, every year? Sometimes it seems like it! The 2007 annual percentage rate of increase in all motor-fuel consumption by U.S. states was reported in the Highway Statistics, November 2008, and is listed in the table. Notice that the consumption did not increase in every state.

a. Explain the meaning of: negative and positive values, large and small values, values near zero, values not near zero.
b. Examine the data in the table.What do you anticipate the distribution of €œpercent change€ to look like? What do you think the mean €œpercent change€ will be? Justify your estimate, without any preliminary work or calculations.
c. If you expect very little or no change, what value will the mean have? Explain.
d. Construct a histogram of the percent of change.
e. Calculate the mean percent of changes in consumption from 2006 to 2007.
f. The Federal Highway Administration reported the percentage increase for the entire United States as 0.4 of 1%. The value calculated for the mean in part e is not the same. Explain how this is possible.

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Percent change in all motor-fuel consumption from 2006 to 2007 by state 2.4 -0.4 0.3 6.8 0.5 1.3 0.3 5 13 -2.1 -0.71.5 4904 -0.8 0. 3.3 03 10.216 1.0 3.0 -2.7 -0.3-2.9 0.9 0.6 3.4 -0.5 9 2.213 -0.4 1.2 4.3 0.1 4.4 0.3 -0.4 -0.9 0. 3.4 1.4 2.6 3.9 1.1 2.1 0.6 -0.6 2. 5.2 Souce: US. Department of Transportation-Federal Highway Administration