Reference no: EM132845651

The annual number of burglaries in a town rose by 50% in 2012 and fell by 20% in 2013. Hence the total number of burglaries increased by 30% over the two-year period.

a. What is the mistaken assumption here? Mistaken assumption is that the % increase and % decrease is calculated on initial annual burglaries.

b. Why is that assumption incorrect? If there were an initial burglary rate of 100 for the prior year, 50% increase of 100 would be 50, 100 + 50 =150, 20% decrease of 150 would be 30, 150 - 30 = 120, 120 is 20% higher than 100, so overall there would be a 20% increase over the two years.

c. By what percent has the number of burglaries actually changed in the two year period? There is an increase in burglaries of 20% over the two years

d. By what percent would the crime have to decrease in the second year in order for the change over the two-year period to actually be a 5% increase?

(105-120)

120 X 100 = -12.5%

The percentage would have to decrease by 12.5% for there to be 5% increase over the two years.