All categories

3 years ago

Someone please help, can’t seem to get the problems

Mathematics

1 answer:

VikaD [51]3 years ago

5 0

Answer:

A) 525,500

B) decreasing by 0.995% per year

C) 430,243

D) After 20 years, the population can be expected to be about 20% smaller.

E) 2009

Step-by-step explanation:

A) t=0 represents the year 2000, so put 0 where t is in the expression and evaluate it. Of course, e^0 = 1, so the y-value is 525.5 thousand, or 525,500.

B) Each year, the population is multiplied by e^-0.01 ≈ 0.99004983, or about 1 - 0.995%. That is, the population is decreasing by 0.995% per year.

C) t represents the number of years since 2000, so the year 2020 is represented by t=20. Put that value in the equation and do the arithmetic.

y = 525.5·e^(-0.01·20) = 525.5·e^-0.2 ≈ 430.243 . . . . thousands

The population in 2020 is predicted to be 430,243.

D) The decrease is about 1% per year, so a rough estimate of the decrease over 20 years is 20%. The population of about 500,000 will decrease by about 100,000 in that time period, so will be about 400,000. The value we calculated is in that ballpark. (The actual decrease is about 18.13%; or about 95.2 thousand.)

E) Your working shows the general idea, but you need to remember the numbers in the equation are thousands:

480 = 525.5·e^(-0.01t)

0.913416 = e^(-0.01t) . . . . divide by 525.5

ln(0.913416) = -0.01·t . . . . take the natural log

-100ln(0.913416) = t ≈ 9.06

The population will be 480 thousand after 9 .06 years, in the year 2009.

You might be interested in

Isabel works for 6 hours preparing for the art fair. She spends 3 hours on a sculpture and then paints 27 picture frames. How mu

Alecsey [184]

Answer: 3?

Step-by-step explanation: 3?

WOOOAH -_-

8 0

3 years ago

A 64-ounce bottle of orange juice has 48 ounces of water . What percent of bottle of orange juice is water

tatyana61 [14]

48 ounces is water, out of 64 ounces of orange juice. 48 out of 64 is 48/64=0.75. That is 0.75*100=75 percent.

7 0

3 years ago

Read 2 more answers

Alinethatincludesthepoint(2, 7)has slope of 5 . what isitsequationin slope -intercept form

Vesna [10]

10? Im not sure though my friend just told me it was 10

8 0

3 years ago

Find out if the 3 positions are on the same line or not (3,2,0) (1, -1,2) (5,5, 2)

sattari [20]

Answer:

The three positions are not on the same line.

Step-by-step explanation:

We have three points: A:(3,2,0), B:(1,-1,2) and C:(5,5,2).

Let's build a vector that goes from one point to another; that vector will be the director of a line (if we draw a vector that goes from A to B, that vector will be the direction of the line that pass by A and B because it does not change). In order to build that vector, let's subtract B from A:

$A-B=(3,2,0)-(1,-1,2)=(2,3,-2)$

The equation of a line is:

$p=p_0+rt$

Where p is every singular point of the line, $p_0$ is a particular point of the line (any that we are sure that it is on the line), r is the director vector and t is the independent variable.

Now we have the director vector: (2,3,-2), and we can verify that A and B are on the line:

$p=p_0+(2,3,-2)t$

Because there is a value for t that satisfies both A and B: If we do $p_0=(3,2,0)$ and t=0, we are going to obtain the point p=A; and if we do t=-1, we are going to obtain p=B. Let's see that:

$p=(3,2,0)+(2,3,-2)*0=(3,2,0)\\p=A\\p=(3,2,0)+(2,3,-2)*-1=(1,-1,2)\\p=B\\$

If C is also in the same line, C must accomplish the equation: $p=(3,2,0)+(2,3,-2)t$ , so:

$C=(5,5,2)=(3,2,0)+(2,3,-2)t$

Let's simplify the equation writing the parametric equation, which is just to write the equation for each dimension:

$5=3+2t\\5=2-3t\\2=-2t\\$

You can verify that there is not a value of t that satisfies all three equations, so, the point C is not on the same line as A and B; which means that A, B and C are not on the same line.

8 0

3 years ago

If a rectangular prism is sliced vertically by a plane, what is the shape of the resulting two dimensional figure?

Romashka [77]

I think 2 triangular prisms.

8 0

3 years ago