Question

which spreadsheet would be used to compute the first 7 terms of the geometric sequence an=20*(1/2)^n-1

Answer 1

Answer:

Option 4

Step-by-step explanation:

Given : Geometric sequence $a_n=20\times (\frac{1}{2})^{n-1}$    

To find : Which spreadsheet would be used to compute the first 7 terms of the geometric sequence  ?

Solution :

Geometric sequence is in the form $a+ar+ar^2+ar^3+...$

Where, a is the first term and r is the common ratio.

The sum of sequence is represented as  $S_n=\sum^{7}_{n=0} ar^n$

or $S_n=\sum^{7}_{n=1} ar^{n-1}$

According to question,

a=20 and $r=\frac{1}{2}$

Sum of first terms is,

$S_1=20(\frac{1}{2})^{n_1-1}$ , $n_1=1$

Sum of second terms is,

$S_2=20(\frac{1}{2})^{n_2-1}$ ,$n_2=2$

Sum of third terms is,

$S_3=20(\frac{1}{2})^{n_3-1}$ ,$n_3=3$

Sum of four terms is,

$S_4=20(\frac{1}{2})^{n_4-1}$ ,$n_4=4$

Sum of five terms is,

$S_5=20(\frac{1}{2})^{n_5-1}$ ,$n_5=5$

Sum of six terms is,

$S_6=20(\frac{1}{2})^{n_6-1}$ ,$n_6=6$

Sum of seven terms is,

$S_7=20(\frac{1}{2})^{n_7-1}$ ,$n_7=7$

Therefore, Option 4 is correct.

The spreadsheet 4 would be used to compute the first 7 terms of the geometric sequence.

Answer 2

The appropriate spreadsheet is the one that makes use of the proper formula and appropriate cell references.