Select the correct answer.

Which type of sequence is represented by the given table?
\begin{tabular}{|c|c|c|c|c|}
\hline [tex]$x$[/tex] & [tex]$1$[/tex] & [tex]$2$[/tex] & [tex]$3$[/tex] & [tex]$4$[/tex] \\
\hline[tex]$y$[/tex] & 4 & -9.6 & 23.04 & -55.296 \\
\hline
\end{tabular}

A. The table represents an arithmetic sequence because the successive [tex]$y$[/tex]-values have a common difference of 4.2.

B. The table represents a geometric sequence because the successive [tex]$y$[/tex]-values have a common ratio of -2.4.

C. The table represents a geometric sequence because the successive [tex]$y$[/tex]-values have a common ratio of 0.4.

D. The table represents an arithmetic sequence because the successive [tex]$y$[/tex]-values have a common difference of -17.



Answer :

To determine the type of sequence represented by the given table, we need to analyze the [tex]$y$[/tex]-values at each step and decide if they show a common difference (arithmetic sequence) or a common ratio (geometric sequence).

Given table:
\begin{tabular}{|c|c|c|c|c|}
\hline
[tex]$x$[/tex] & [tex]$1$[/tex] & [tex]$2$[/tex] & [tex]$3$[/tex] & [tex]$4$[/tex] \\
\hline
[tex]$y$[/tex] & [tex]$4$[/tex] & [tex]$-9.6$[/tex] & [tex]$23.04$[/tex] & [tex]$-55.296$[/tex] \\
\hline
\end{tabular}

1. Check for Arithmetic Sequence:

An arithmetic sequence has a common difference ([tex]$d$[/tex]) between successive terms, which means:
[tex]\[ y_{i+1} - y_i = d \][/tex]

- Calculate the difference between the first and second [tex]$y$[/tex]-values: [tex]\(-9.6 - 4 = -13.6\)[/tex]
- Calculate the difference between the second and third [tex]$y$[/tex]-values: [tex]\(23.04 - (-9.6) = 23.04 + 9.6 = 32.64\)[/tex]
- Calculate the difference between the third and fourth [tex]$y$[/tex]-values: [tex]\(-55.296 - 23.04 = -55.296 - 23.04 = -78.336\)[/tex]

Since the differences are not the same, the given table does not represent an arithmetic sequence.

2. Check for Geometric Sequence:

A geometric sequence has a common ratio ([tex]$r$[/tex]) between successive terms, which means:
[tex]\[ \frac{y_{i+1}}{y_i} = r \][/tex]

- Calculate the ratio between the first and second [tex]$y$[/tex]-values: [tex]\(\frac{-9.6}{4} = -2.4\)[/tex]
- Calculate the ratio between the second and third [tex]$y$[/tex]-values: [tex]\(\frac{23.04}{-9.6} = -2.4\)[/tex]
- Calculate the ratio between the third and fourth [tex]$y$[/tex]-values: [tex]\(\frac{-55.296}{23.04} = -2.4\)[/tex]

Since all the ratios are equal to [tex]\(-2.4\)[/tex], the table represents a geometric sequence with a common ratio of [tex]\(-2.4\)[/tex].

Therefore, the correct answer is:
B. The table represents a geometric sequence because the successive [tex]$y$[/tex]-values have a common ratio of -2.4.

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