Question

Please Help Me

Answer 1

with?

Answer 2

What do you need help with

Answer 3

Scientists studied two animal populations. Function f(x) = 830(0.8)x models a bear population in a given region x years after the study began. The table models the cougar population in the same region.

Use the table of data to interpret a linear function.
Which statement is true?



The bear population is decreasing at a rate that is about twice that of the cougar population.

The bear population is decreasing at a rate that is about three times that of the cougar population.

The cougar population is decreasing at a rate that is about twice that of the bear population.

The cougar population is decreasing at a rate that is about three times that of the bear population.

Answer 4

@Michele_Laino

Answer 5

Is there another table?

Answer 6

no

Answer 7

Well I don't know how to help you there.. we don't have the bear's population

Answer 8

Nvm. The function

Answer 9

I'd go with selection C. I had made a graph on paper but there's no way for me to show you the graph.

Answer 10

I'd help give me a minute

Answer 11

try making the bear population into a table first. so f(x) = 830(.8)x so solve for different variables of x, x being years after the study began. so if x = 1, then f(x) = 664. if x = 2, then f(x) = 1328. the bear's population is INCREASING, not decreasing.

Answer 12

i believe i did that correctly lol, but obviously that's not one of the answers. :/

Answer 13

@kah.x That happens to me sometimes, but your work is the reason I initially picked "c".

Answer 14

@xmissalycatx I'm confused, are you saying im correct or incorrect? i won't take offense if you think I'm wrong haha

Answer 15

Did you do the math?

Answer 16

There's a function for the bears popular

Answer 17

I believe that it was C from the beginnig but i wanted to see what someone else thought

Answer 18

i did the math using the bear function, but i'm not sure my math is correct since it's not one of the options for the answer

Answer 19

@kah.x I agreed with part of it. I don't think the bears are positive though..

Answer 20

we have two functions:
population of bears can be modeled by this function:\[N{\text{ }} = {\text{ }}830 \cdot {\left( {0.8} \right)^Y}\]

whereas cougars population can be modeled by this function, as we have found, in the previous exercise:
\[N = 790 \cdot {\left( {0.93} \right)^Y}\]

Answer 21

I'd go with C too I did the math

Answer 22

@Michele_Laino we just did this and I'm thinking what number goes in the y place

Answer 23

\(Y\) is a variable

Answer 24

ohh, listen to @michele_liano i didn't get that the equation had an exponent because it wasn't typed that way in your question. next time make sure to use a ^ to indicate that there's an exponent :)

Answer 25

@kah.x im sorry. and @Michele_Laino 734.7

Answer 26

Wihch one is the correct answer?

Answer 27

here, we have to understand how is defined the rate of increasing or decreasing

Answer 28

@Michele_Laino since we got 40 for our last answer, I thought it would be decreasing twice

Answer 29

so let's try this again. try making a table from the bear function. if x=1, then 830(.8)^x = 664. if x=2, then it's 531.2. you can find the rate of decrease by dividing the second number by the first, so 531.2/664. it's decreasing at a rate of .8, or 80 percent. you could find this from just looking at the problem, but I wanted to show you how to find it from the table as well. so for the cougars then, find the rate of decrease. (735/790) then you have the rate of decrease for that as well and you can tell which one is decreasing faster and how much faster

Answer 30

did that make sense?

Answer 31

nice job!! @kah.x

Answer 32

@freemap please follow the advice of @kah.x

Answer 33

ok so 735 is the bear population and 790 is the cougar population?

Answer 34

I'm confused

Answer 35

no, 735 is the cougar population after 1 year and 790 is the cougar population after 0 years. divide 735/790. what do you get?

Answer 36

hint:
decreasing rate for bears population, is: \((664/830) \cdot100=...\%\)
decreasing rate of cougar population is: \((735/790) \cdot 100=...\%\)

Answer 37

@kah.x .93

Answer 38

okay, so the rate of decrease is .93, which is 93%

Answer 39

for cougars

Answer 40

and the bear decrease is 80%, which one is decreasing faster?

Answer 41

the cougars

Answer 42

The cougars are decreasing faster

Answer 43

okay, and how much faster? the options are either twice as fast or three times as fast

Answer 44

Well i guess three times as fast because twice isn't right

Answer 45

wait one second, i said something wrong.

Answer 46

the rate of INCREASE is 80% and 93%. the bears are actually decreasing faster.

Answer 47

So A

Answer 48

i believe so

Answer 49

Is it A for sure

Answer 50

\( f(x) = 830(0.8)^x\) shows a rate of decrease of 20% per year.

Answer 51

So that represents, twice right

Answer 52

Now for the cougars, you use the table.
Let's look at the first two data points:
(0, 790)
(1, 735)

\(\dfrac{735-790}{790} \times 100 = -7\%\)

Let's look at the data points corresponding to years 2 and 6:

\(\dfrac{511-683}{683} \times 100 = -25\%\)

Since this decrease was over a period of 4 years (year 2 to 6), dividing by 4, you get an average decrease of approximately 6.3%. This is not too far from the 7% decrease in years 0 to 1.

Answer 53

ok

Answer 54

The difference between 20% and 7% is about 3 times.

Answer 55

The bear population is decreasing at a rate approximately 3 times greater than the cougar population.

Answer 56

Thank so much

Answer 57

You're welcome.