Open Streets Initiatives temporarily close streets to motorized traffic and open them for jogging, bicycling, and other physical activities. The numbers of large cities with Open Streets Initiatives are shown in Table 41 for various years.
Table 41
Numbers of Large Cities with Open Streets Initiatives
Year Number
2006 …………………….. 1
2007 …………………….. 2
2008 …………………….. 8
2009 …………………….. 7
2010 ……………………..12
2011 ……………………..22
2012 ……………………..30
a. Construct a time-series plot.
b. Have the number of large cities with Open Streets Initiatives generally increased, decreased, stayed approximately constant, or none of these?
c. Find the greatest change in the number of large cities with Open Streets Initiatives from one year to the next.
d. Find the change in the number of large cities with Open Streets Initiatives from 2006 to 2012. If the number of large cities with Open Streets Initiatives changes by that same amount from 2012 to 2018, what will it be in 2018? Do you have much faith that this will turn out to be true? Explain.