Apply the problem-solving techniques to solve the following
problem.
Population decrease In 1990, a rural area had 1200 bird
species. If species of birds are becoming extinct at the rate of
1.5% per decade (10 years), how many bird species will there be
left in the
year
2020?

Answers

Answer 1

Answer:

By 2020, there will be 1,147 species of birds left

Step-by-step explanation:

The general model for an exponential decrease is;

y = I(1 - r)^t

where in this case;

y is the number of bird species at a particular decade from the initial

I is the number of birds initially at 1990

r is the decrease percentage which is 1.5% per decade ; 1.5% = 1.5/100 = 0.015

t in this case will be the number of decades after the initial

Mathematically, a decade is 10 years

The difference between 2020 and 1990 is 30

The number of decades in 30 years is 30/10 = 3

so t will be 3 here

Substituting these values into the equation, we have

y = 1200(1-0.015)^3

y = 1200(0.985)^3 = 1,146.8

To the nearest whole number, this is 1,147


Related Questions

Tell whether the angles are adjacent or vertical. Then find the value of x. The angles are . Question 2 x=

Answers

Answer:

Adjacent

x = 14

Step-by-step explanation:

Find the diagram attached

Adjacent angles places side by side and can also be on the same straight line. Since 5x and x+96 are on the same straight line ans placed side by side, then the angles are adjacent.

The sum of angle on a straight line is 180 degrees, hence;

5x + x+ 96 = 180

6x = 180 - 96

6x = 84

x = 84/6

x =14

The value of x s 14

7. Jerry has 23 coins in nickels, n, and dimes, d. He
has $1.95 altogether. How many nickels does Jerry
have?

Answers

Answer:

17 nickles !

Step-by-step explanation:

First, identify the variables:

n = amount of nickels

d = amount of dimes

Next, setup the equations based on what you know.  The first equation is:

n + d = 28

For the second equation, we know that a dime is worth 10¢ and a nickel is 5¢, so it should be:

0.05n + 0.10d = 1.95

This a three-step answer:

In one formula (you can use any of them; most people use the simplest one), single out the variable on one side

Apply the first formula into the second formula, and solve it to get the value of one variable

Apply the answer from the second formula into the first formula, and solve it to get the value of the other variable

======

Step One:

n + d = 28

n + d - d = 28 - d

n = 28 - d

Step Two:

0.05n + 0.10d = 1.95

(0.05 * (28 - d)) + 0.10d = 1.95

1.40 - 0.05d + 0.10d = 1.95

1.40 + 0.05d = 1.95

1.40 - 1.40 + 0.05d = 1.95 - 1.40

0.05d = 0.55

d = 11

Step Three:

n = 28 - d

n = 28 - 11

n = 17

======

Your answer should be 17 nickels and 11 dimes.

You can double check by applying the variables into both formulas.

n + d = 28

17 + 11 = 28

28 = 28

0.05n + 0.10d = 1.95

(0.05 * 17) + (0.10 * 11) = 1.95

0.85 + 1.10 = 1.95

1.95 = 1.95

I hope this helped.

Simplify the expression below.

4x+ 3(2x−1) − 4x

Answers

Answer:

=6x−3

Step-by-step explanation:

Let's simplify step-by-step

4x+3(2x−1)−4x

Distribute:

=4x+(3)(2x)+(3)(−1)+−4x

=4x+6x+−3+−4x

Combine Like Terms:

=4x+6x+−3+−4x

=(4x+6x+−4x)+(−3)

=6x+−3

Answer:

6x - 3

Step-by-step explanation:

4x + 3(2x - 1) - 4x

Distribute, multiply every term inside the parenthesis by the term outside of it,

4x + (3)(2x) + (3)(-1) - 4x

Simplify,

4x + 6x - 3 - 4x

Simplify further, combine like terms,

6x - 3

In which step did John first make a mistake?
look at photos

Answers

Answer:

John did not make a mistake

Step-by-step explanation:

he did everything correct

he didn’t make a mistake

Use the information from the graphs to write the equation in y=ab*^x

Answers

Answer:

1). y = 4(1.75)ˣ

2). y = (2)ˣ

Step-by-step explanation:

1). Let the equation of the given exponential graph is,

y = a(b)ˣ

Graph of the given equation passes through two points (0, 4) and (0+1, 4+3)

For point (0, 4),

4 = a(b)⁰

a = 4

For point (1, 7),

7 = 4(b)¹

b = [tex]\frac{7}{4}[/tex]

b = 1.75

Therefore, equation of the function is,

y = 4(1.75)ˣ

2). Similarly, equation of the second graph will be same in the form of

y = a(b)ˣ

Second graph passes through the points (0, 1) and (2, 4)

For (0, 1),

1 = a(b)⁰

a = 1

For (2, 4),

4 = 1(b)²

b = 2

Therefore, exponential function representing the graph will be,

y = 1(2)ˣ

y = 2ˣ

Sin(x)=sqrt3/2 solutions of

Answers

Answer:

pi/3+2pin, 2pi/3+2pi(n)

Answer:

the next one is c - pi/2

Step-by-step explanation:

a recipe for bread uses 2 cups of liquid and 6 cups of flour for 3 loaves of bread. how many cups of flour are needed for 10 loaves and how much liquid is needed if 21 cups of flour are used?

Answers

10

Step-by-step explanation:

I just did this in a lesson

Margaret owns (5/6) of a section of land. She planted corn on (1/4) of her land. What fraction of the entire section is planted with Margaret’s corn?

Answers

Answer:

3/5

Step-by-step explanation:

subtract the fractions then turn the decimal into a fraction.

is y = 7/8x proportional or non-proportional??

Answers

Answer:

It is proportional

Step-by-step explanation:

May have brainllest I only need 39 more to get to genius

can some give me the anwsers

Answers

Answer:

150 -160

Step-by-step explanation:

I not amazing at this but i do know this is kinda hard. sorry if it is wrong

Need ASAP! Will give brainliest!

Answers

Try the second one B

What is the area of the base ? / / / / /

Answers

Answer:

area of base = 20 in²

Step-by-step explanation:

area of base = 2 x 10 = 20 in²

A boat covers 25 km upstream and 44 km downstream in t hours. Also, it covers 15 km upstream and 22 km downstream in 5 hours. Find the speed of the boat in still water and that of the stream.​

Answers

9514 1404 393

Answer:

  boat speed: (7t -95)/(6t² -110t +500)

  stream speed: (37t -345)/(6t² -110t +500)

Step-by-step explanation:

The relation between time, speed, and distance is ...

  time = distance/speed

The boat speed (b) is added to the stream speed (s) going downstream. The stream speed is subtracted going upstream. The given relations tell us ...

  25/(b-s) +44/(b+s) = t

  15/(b-s) +22/(b+s) = 5

This gives us 2 equations in 3 unknowns, so we can only provide a solution in terms of one of the unknowns. Since we are asked for the speeds, they will be provided in terms of t.

Subtracting the first equation from 2 times the second gives ...

  2(15/(b-s) +22/(b+s)) -(25/(b-s) +44/(b+s)) = 2(5) -(t)

  5/(b-s) = 10 -t

  5/(10 -t) = b -s

Substituting for b-s in the second equation gives ...

  15/(5/(10-t)) +22/(b+s) = 5

  30 -3t +22/(b+s) = 5

  22/(b+s) = 3t -25

  22/(3t -25) = b+s

Adding the equations for the sum and difference of speeds, we get ...

  (b-s) +(b+s) = 5/(10-t) +22/(3t -25)

  2b = (5(3t -25) +22(10 -t))/((10-t)(3t-25)) = (95 -7t)/((10-t)(3t-25))

  b = (7t -95)/(6t² -110t +500)

Subtracting the equations for sum and difference of speeds, we get ...

  (b+s) -(b-s) = 22/(3t -25) -5/(10 -t)

  2s = (22(10-t) -5(3t -25))/((10-t)(3t-25))

 s = (37t -345)/(6t² -110t +500)

__

The speed of the boat in still water is (7t -95)/(6t² -110t +500) km/h.

The speed of the stream is (37t -345)/(6t² -110t +500) km/h.

__

Note that these solutions only make sense for values of t between 25/3 and 345/37, approximately 8.33 < t < 9.32. For t=9 hours, the boat speed is 8 km/h and the stream speed is 3 km/h.

HELPPPPPPP!!!!!!!!!!!!!!​

Answers

Answer:

the top and bottom ones

Step-by-step explanation:

Help ASAP, ACD and DCB form a linear pair

Answers

Answer:

40

Step-by-step explanation:

because 180- 140 = 40

a linear pair means they equal 180

The measure of angle ACD (∠ACD) is 40 degrees.

Given that angles ACD and DCB forms a linear pair, also m ∠DCB = 140°,

We are asked to find the measure of ∠ACD,

So,

If angles ACD and DCB form a linear pair, it means that their sum is equal to 180 degrees.

Let's denote the measure of angle ACD as x.

So, we have the equation:

m∠ACD + m∠DCB = 180°

Substituting the given value for m∠DCB:

x + 140° = 180°

To solve for x, we can subtract 140° from both sides of the equation:

x = 180° - 140°

x = 40°

Therefore, the measure of angle ACD (∠ACD) is 40 degrees.

Learn more about linear pair click;

https://brainly.com/question/1757859

#SPJ2

It takes 76 pounds of seed to completely plant an 11-acre field. How many pounds of seed are needed per acre?​

Answers

Answer:

6 pounds and 9 ounces

or 7 pounds when rounded

PLEASE HELP. no links.

Answers

Answer:

45 i think

Step-by-step explanation:

PLZZZ ANSWER HURRY 25 POINTS

Answers

Answer:

3

Step-by-step explanation:

When ringing up a customer, a cashier needs 10 seconds to process the payment as well as 5.7 seconds to scan each item being purchased. Write an equation that shows the relationship between the items being purchased, p, and the time, t.

Answers

Answer: 5.7p + 10

Step-by-step explanation:

From the question, we are given the information that when ringing up a customer, the cashier will need 10 seconds to process the payment and 5.7 seconds to scan every item that are purchased.

The equation that shows the relationship between the items being purchased, p, and the time, t will then be:

= 5.7p + 10

Expand the expressions below using a rectangular array.

42g+r−5

Answers

Answer:

42g + r - 5 =0

Step-by-step explanation:

explain how you can tell whether a group of ratios represents a proportional relationship. PLEASE HELP

Answers

Ratios are proportional if they represent the same relationship. One way to see if two ratios are proportional is to write them as fractions and then reduce them. If the reduced fractions are the same, your ratios are proportional.

hope this helps :)

Question 5 1 To get from my home to my school, I travel approximately 4.1 miles east, then approximately 4.7 miles north. What is the approximate distance from my home to my school, rounded to the nearest tenth of a mile? * School Distance Home 90°​

Answers

Answer:

I hope you find the answer

Ms. Ruiz has a piece of fabric that is 3 3/4 yards long. She waves to cut it into 12 equal pieces. How many yards will each piece of fabric be

Answers

Answer:

the number of yards be 0.3125

Step-by-step explanation:

The computation of the number of yards will each piece of fabric be is shown below:

Given that

There is [tex]3 \frac{3}{4}[/tex] yards long i.e. 15 ÷ 4

And, it should be cut into 12 equal pieces

So, the number of yards   will each piece of fabric be is

= 15 ÷ 4 ÷ 12 ÷ 1

= 15 ÷ 48

= 0.3125

Hence, the number of yards be 0.3125

Answer:

5/16

Step-by-step explanation:

3 3/4= 13/4

13/4 ÷ 12= 0.3125

0.3125 = 5/16

Find the value of x if 2x = 20 .​

Answers

Answer:

x = 10

Step-by-step explanation:

Divide both sides by 2.

(2x) / 2 = 20 / 2

x = 10

Answer:

The answer is going to be 10.

Step-by-step explanation:

1) Diving both sides by 2.

[tex]x = \frac{20}{2} [/tex]

2) Simplify 20/2 to 10 because 20 ÷ 2 is 10.

[tex]x = 10[/tex]

Therefor, the answer for x is x = 10.

you want to insert a fill color into a worksheet. what is the first step . Plzz help I’m literally stuck

Answers

you forgot to attach an image!! please repost.
can you make another one showing us the pic pls?

Urgent please help..

Answers

108 !! ye i’m sorry mate i suck at maths

Answer: I’m pretty sure it’s 15 cm

Step-by-step explanation:

Complete the following table using the equation: y = x squared
x
-3
-1
0
1
3
y


Plot the points on a graph and determine which graph best represents the equation.
Graph A
On a coordinate plane, a parabola opens up and goes through (negative 2, 4), has a vertex at (0, 0), and goes through (2, 4).
Graph B
On a coordinate plane, a parabola opens down and goes through (negative 2, negative 4), has a vertex at (0, 0), and goes through (2, negative 4).
a.
-9, -1, 0, -1, -9; Graph B
b.
9, 1, 0, 1, 9; Graph B
c.
9, 1, 0, 1, 9; Graph A
d.
-9, -1, 0, -1, -9; Graph A

Answers

Answer:

Step-by-step explanation:

ITS A

Answer:

The answer is C , Graph A

Step-by-step explanation:

*WILL GIVE BRAINLIEST FOR THE BEST ANSWER NO VIRUS LINKS OR ILL REPORT YOU*

Which of these statements best describes a biased sample?



A. The sample is small



B. The sample has results that are incorrect predictions



C. The sample does not accurately represent the population



D. The sample was chosen randomly

Answers

Answer:

C) The sample does not accurately represent the population

Answer:

C

Step-by-step explanation:

If you go to go   o   g  l    e and search up "bias sample examples" it will give you examples! I hope I helped :)

PLEASE HELP ASAP PLEASE ​

Answers

The median means number in the middle.
in order it would be -3, 1, 3, 3, 6
the number in the middle is 3
so the median of this sequence is 3 ! :)

Answer:

3

plz follow me

potphcloysidyodoyzyozlhph

Please help, i dont understand this

Answers

Answer:

lgma

Step-by-step explanation:

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