30 POINTS!!!!!!
The population of a local species of beetle can be found using an infinite geometric series where a1 = 960 and the common ratio is one fourth. Write the sum in sigma notation, and calculate the sum (if possible) that will be the upper limit of this population.

Respuesta :

Answer: The sum that will be the upper limit of this population is 1280.

Step-by-step explanation:

Since we have given that

Initial population a₁ = 960

Common ratio = [tex]\frac{1}{4}[/tex]

So, We have to write the sum in sigma notation:

[tex]\sum (ar^{n-1})\\\\=\sum 960(\frac{1}{4})^{n-1}\\\\[/tex]

Since [tex]r=\frac{1}{4}<1[/tex]

so, the sum is convergent, then,

[tex]\sum 960(\frac{1}{4})^{n-1}=\frac{a}{1-r}=\frac{960}{1-\frac{1}{4}}=\frac{960}{\frac{3}{4}}=\frac{960\times 4}{3}=320\times 4=1280[/tex]

Hence, the sum that will be the upper limit of this population is 1280.

Answer with explanation:

→Infinite Geometric Series

[tex]a_{1}=960\\\\r=\frac{1}{4}[/tex]

→The geometric series having common ratio r, and first term a,can be written as:[tex]a, ar,ar^2,ar^3,ar^4,.......[/tex]

→So, the geometric Series can be Written as:

[tex]960, 960 *\frac{1}{4},960*[\frac{1}{4}]^2,960*[\frac{1}{4}]^3,......\\\\ 960,240,60,15,.....[/tex]

→Sum of Infinite geometric Series

=960+240+60+15+.......

[tex]={S_{\text{Infinity}}=\sum_{n=1}^{\infty }960*r^{n-1}=\frac{a}{1-r}[/tex]

[tex]=\frac{960}{1-\frac{1}{4}}\\\\=\frac{960*4}{3}\\\\=320*4=1280\\\\=\frac{a}{1-r}[/tex]

Sum ,to infinity, Which is upper limit of this population=1280