Acountry currently has a population of 100 million and an annual growth rate of 3.5 percent. if the growth rate remains constant, what will be the population of this country in 40 years?
a. 150 million
b. 200 million
c. 300 million
d. 400 million
e. 800 million

The population after 40 years will be 400 million

Explanation:

To calculate population of a country after 40 years,, we use the equation:

A = Population after time period 'T'

P = Current population = 100 million

R = rate of interest = 3.5 %

n = Number of times interest applied per time period = 1   (annually)

T = time period = 40 years

Putting values in above equation, we get:

Hence, the population after 40 years will be 400 million

this null effect is caused by a weak manipulation and ineffective internal validity. in a scientific study, as the one dr. morimoto is trying to perfom, internal validity refers to the confidence placed in the cause-effect relationship and to how well an experiment is done and able to eliminate confounding variables.