The answer and process are in the picture.
Answer:

The world population at the beginning of 2019 will be of 7.45 billion people.
Step-by-step explanation:
The world population can be modeled by the following equation.

In which Q(t) is the population in t years after 1980, in billions, Q(0) is the initial population and r is the growth rate.
The world population at the beginning of 1980 was 4.5 billion. Assuming that the population continued to grow at the rate of approximately 1.3%/year.
This means that 
So


What will the world population be at the beginning of 2019 ?
2019 - 1980 = 39. So this is Q(39).


The world population at the beginning of 2019 will be of 7.45 billion people.
So Congruent. Two figures are congruent if they have the same shape and size. Two angles are congruent if they have the same measure. Two figures are similar if they have the same shape but not necessarily the same size.
I hope that help u:)
- Midpoint Formula:

So firstly, let's start with the x-coordinates. Since we know the midpoint's x-coordinate and point A's x-coordinate, we can solve for point B's x-coordinate as such:

Next, do the same thing except solve for the y-coordinate and using point A's y-coordinate and the midpoint's y-coordinate:

<u>Putting it together, point B's coordinates are (2,4).</u>