The number of crimes that occurred in a certain city per 1000 people had decreased from
46.6 in 1920 to 45.1 in 1970. Find the average rate of change in the number of crimes per 1000 people that occurred from 1920 to 1970.
Average rate of change (per year) =
[ 46.6 - 45.1 ] / [ 1920 - 1970 ] =
1.5 / -50 =
-.03 crimes per year
45.1 / 46.6 =0.9678 - 1 x 100 =-3.22% decrease in crime over a period of 50 years!. [1 + (-0.0322)]^(1/50) =0.9678^(1/50) - 1 x 100 =-0.0654% - average decrease in crime rate PER YEAR over a period of 50 years!.
