Population growth in 7 years

Question

Ydd97 2019-11-15

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/491264-population-growth-in-7-years

评论： Hend Nasrallah 2021-6-24

Hi,

I want to make a graph that will calculate how the population will change in 7 years in a spesific country. Say in 2018 there is approximately 5 million people in a country, and the growth rate is 0.63%. What will the approximated population be in 2025? Is there anyone that can help me code this.

I have already calculated this using expontential euqation:

y= a(1+r)^t

P = 5(1.0063)^7

P = 5.22 million

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Answer 1

Fabio Freschi 2019-11-15

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https://ww2.mathworks.cn/matlabcentral/answers/491264-population-growth-in-7-years#answer_401650

% rate
r = 0.0063;
% years
t = 7;
% initial population
a = 5e6;
% population
y = a*(1+r)^t

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Fabio Freschi 2019-11-15

you must create a vector for the years and for the populations. For this you can use a for loop

for i = 1:7
    t(i) = i;
    y = a*(1+r)^t(i);
end
figure,plot(t,y)

or, better, use a vectorized notation

t = 1:7;
y = a*(1+r).^t;
figure,plot(t,y);

Hope it helps.

Please accept the answer if you are satisfied

Hend Nasrallah 2021-6-24

Hi i tried doing this question but the figure is not showing anything, it just giving me blank figure can I know what is the problem with the command ?

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