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.
Answer:
6400
Step-by-step explanation:
its 6400 to the nearest hundred
Answer:
Sum of Interior Angles = 900°
One Interior Angle = 128.57°
Step-by-step explanation:
We know that the figure is a Heptagon (a 7 sided polygon), therefore;
→ As by the formula of (n - 2) * 180° we can find the sum of the interior angles;
=> (n - 2) * 180 = Sum of Interior Angles
=> (7 - 2) * 180 = Sum of Interior Angles
=> 5 * 180 = Sum of Interior Angles
=> <u>900° = Sum of Interior Angles</u>
Now that we know the sum of interior angles,
→ We can find 1 interior angle by dividing the sum by the number of sides in the polygon.
=> Sum of Interior Angles / n = One Interior Angle
=> 900 / 7 = One Interior Angle
=> <u>128.57° = One Interior Angle</u>
Hope this helps!
New pump = (Old Pump * Total) / (Old Pump - Total)
New pump = (14 * 6) / (14 -6)
New pump = (84) / (8)
New Pump = 10.5 hours