Question

Erosion decreases the size of a small Caribbean island that has a current area of 722 acres. If the island’s area decreases at the rate of 0.06%, find the multiplier for the rate of exponential decay.


Select one:


a. 1.06

b. 1.0006

c. 0.854

d. 0.9994

Answer 1

@phi @kc_kennylau @DangerousJesse @hartnn

Answer 2

if you multiply by a number bigger than 1, you get a bigger number
example: 722*1.06 (notice 1.06 is bigger than 1) and you get 765.32

if you multiply by a number less than 1, you get a smaller number

Answer 3

they say
area decreases

meaning the area gets smaller. Do we multiply by a number bigger than 1 or less than 1 ?

Answer 4

bigger?

Answer 5

they say the area 722 *decreases* (gets smaller)

if you multiply by a number bigger than 1, you get a bigger number
if you multiply by a number less than 1, you get a smaller number

do we want to multiply by a number bigger than 1 or less than 1 ?

Answer 6

ok less than 1

Answer 7

so you have two choices. to find the correct answer.
subtract the *rate* from 1

the rate is 0.06%
first, can you change that from a percent to a decimal ? (you divide by 100)

Answer 8

-0.999994?

Answer 9

@phi

Answer 10

am I correct

Answer 11

\(1-.0006=?\)

Answer 12

close, but too many 9's

however, you should be able to pick out the correct answer.

Answer 13

D? right

Answer 14

what you should have done is change 0.06% to 0.0006
then do
1-0.0006
you get a *positive number* that is smaller than 1

Answer 15

is it still 0.9994

Answer 16

yes.

Answer 17

thnx broski

Answer 18

yw