QUESTION 2

The population of the world was 7.1 billion in 2013, and the observed relative growth rate was 1.1% per year. A) Estimate how lo

VLD [36.1K]

Answer:

A) 63.36 years.

B) 100.42 years.

Step-by-step explanation:

We have been given that the population of the world was 7.1 billion in 2013, and the observed relative growth rate was 1.1% per year.

A) Since we know that population increases exponentially, therefore we will use our given information to form an exponential model for population increase and then we will solve for the time by which our population will be double.

$P(t)=7.1(1.011)^{t}$

$7.1 \times 2=7.1(1.011)^{t}$

$\frac{7.1 \times 2}{7.1} =(1.011)^{t}$

$2 =(1.011)^{t}$

Now let us solve for t using logarithm.

$ln(2) =ln (1.011)^{t}$

$ln(2) =t \cdot ln(1.011)$

$0.6931471805599453 =t \cdot 0.0109399400383344$

$t=\frac{0.6931471805599453}{0.0109399400383344}$

$t=63.3593217267282743049\approx 63.36$

Therefore, it will take 63.36 years the population to be double.

B) Now we will find the number of years it will take the population to be triple of its size.

$7.1 \times 3=7.1(1.011)^{t}$

$\frac{7.1 \times 3}{7.1} =(1.011)^{t}$

$3 =(1.011)^{t}$

Now let us solve for t using logarithm.

$ln(3) =ln (1.011)^{t}$

$ln(3) =t \cdot ln(1.011)$

$1.0986122886681097 =t \cdot 0.0109399400383344$

$t=\frac{1.0986122886681097}{0.0109399400383344}$

$t=100.4221490079915311298\approx 100.42$

Therefore, it will take 100.42 years the population to triple of its size.

6 0

2 years ago

I need help on these question ASAP!!!! This is Urgent

GarryVolchara [31]

Part 1: The equation of the line is $y=2x+1$

Part 2: The equation of the line in slope intercept form is $y=-3x-1$

Explanation:

Part 1: It is given that the point A is $(1,3)$ and the line B is $y=2 x-2$

To determine the line passing through the point A and parallel to line B, let us first determine the slope and y-intercept.

From the equation of line B, the slope is $m=2$

Substituting the point $(1,3)$ and $m=2$ in slope intercept form $y=mx+b$ , we have,

$3=2(1)+b$

$3=2+b$

$1=b$

Thus, the y-intercept is $b=1$

Let us substitute the values $m=2$ and $b=1$ in the slope intercept form $y=mx+b$ , we get,

$y=2x+1$

Thus, the equation of the line passing though point A and parallel to line B is $y=2x+1$

Part 2: The given two coordinates are $(-1,2)$ and $(1,-4)$

To determine the equation of line in slope intercept form, first we shall find the slope and y-intercept.

From the graph, we can see that the line touches the y-axis at -1.

Hence, the y-intercept is $b=-1$

The formula for slope is $m=\frac{y_{2}-y_{1}}{x_{2}-x_{1}}$

Substituting the coordinates $(-1,2)$ and $(1,-4)$ , we have,

$m=\frac{-4-2}{1+1} =\frac{-6}{2} =-3$

Thus, the slope is $m=-3$

Substituting the values $b=-1$ and $m=-3$ in the slope intercept formula $y=mx+b$ , we get,

$y=-3x-1$

Thus, the equation of the line in slope intercept form is $y=-3x-1$

4 0

3 years ago

A friend of yours, a senior, took the Graduate Record Exam in September and scored in the 99th percentile. InFebruary, your frie

Alecsey [184]

Answer:

"differential selection"

Step-by-step explanation:

If your friend took the test twice and passed both times with a score above 90% then the minor difference in price is most likely due to "differential selection". The first test had questions that he had a little more experience in solving, while the second time he was most likely given a couple questions that he wasn't as prepared for as he was the first time. This is most likely the cause for the difference in percentiles.

I hope this answered your question. If you have any more questions feel free to ask away at Brainly.

3 0

3 years ago

After dans holiday. Dan has 50 new email messages in his inbox . 13 of them are attachements. what proportion of the email messa

dimulka [17.4K]

Answer:

26%

Step-by-step explanation:

Given that Dan has 59 new email messages and 13 have attachment then the proportion that have attachments may be expressed as a ratio of the number with attachments to the total number of emails.

Hence proportion of the email messages have attachments as a percentage

= 13/50 * 100%

= 26%

This means that 26% of the emails received have attachments

6 0

3 years ago

Help me out now Please I'm stuck on this

Elena-2011 [213]

5x + 2(x + 1) ≤ 23

Distribute the 2.

5x + 2x + 2 ≤ 23

Combine like terms.

7x + 2 ≤ 23

Subtract 2 from both sides.

7x ≤ 21

Divide both sides by 7

x ≤ 3

8 0

3 years ago