Explanation: _______________ Price starts at: $7.37. __________________ The first month, it increases by $0.50, so we add $0.50 to that starting value: __________________ $ 7.37 + 0.50 ___________ $ 7.80 _____________ The second month, it decreases by $0.38, so we subtract $0.38 from our last obtained value: ___________________ $ 7.80 - 0.38 ___________ $ 7.42 ______________ During the third month, it increases by $0.32, so we add $0.32 to our last obtained value: ______________ $ 7.42 + 0.32 ___________ $ 7.74 ______________ During the fourth month, it decreases by $0.12, so we subtract $0.12 from our last obtained value: ________________________ $ 7.74 - 0.12 ___________ $ 7.62; which is our answer. _____________ How do we know our answer is reasonable? ______________ We start with: $7.37, then plus $0.50, then minus 0.38, then plus 0.32, then minus 0.12. _______________ The "minus 0.38"and "plus 0.32" do not "cancel out" , but come close to. The "plus 0.50" and "minus 0.12"; in consideration with the above sentence; suggest that the value should be over the starting price of $7.37, but not much more than $8.00; or even less than $8.00. Our answer is: $7.62; which seems "reasonable". __________________________
