
Vasumathi N. answered 02/26/21
Effective Math Tutor . Cater to Various Learning Styles.
I will model this problem as
b = a (1- r)t
where "a" represents the value of the car in 1991, "b" represents the value of the car in 2008, "r" is the rate of change in the value of the car, and "t" is the time in years. Here t= 2008-1991 = 17 years.
To find :r
Substituting the values,
14,000 = 43,000 (1 - r) 17
Dividing both sides by 14,000,
14,000 43,000 (1- r)17
---------- = ----------
14,000 14,000
1 = 3.071428 (1- r)17
dividing by 3.071428,
1
---------- = (1 - r)17
3.071428
We raise both sides to the power (1/17).
(1 /3.071428)(1/17) = (1 - r)
0.93612 = 1 - r
r = 1- 0.93612 = 0.06387
Part 1- Round your answer to 4 decimal places. r = 0.0639
Part 2 - answer as a Percent ; Multiply the answer in part 1 by 100 and you get r = 6.39%
Note: Please use this only as an example. You have the right to ask questions and also the responsibility to check. Go back to your notes/text book ,pull out your calculator and let me know anything you discovered!