Find $a _ { 1 }$ And and R for a Geometric Sequence

question 56

Multiple Choice

Find $a _ { 1 }$ and and r for a geometric sequence { $\left\{ a _ { n } \right\}$ } from the given information.
- $a _ { 2 } = - 6$ and $a _ { 6 } = - \frac { 243 } { 128 }$

• A) \(a _ { 1 } = 8\) and \(r = \frac { 3 } { 4 }\)
• B) \(a _ { 1 } = - \frac { 32 } { 3 }\) and \(r = - \frac { 3 } { 4 }\)
• C) \(a _ { 1 } = 8\) and \(r = - \frac { 3 } { 4 }\)
• D) \(a _ { 1 } = 8\) and \(r = - \frac { 4 } { 3 }\)

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Definitions:

Internally Valid

The extent to which a research study provides evidence of a cause-and-effect relationship between variables, within the context of the study.

Confounds

Variables that researcher failed to control, or eliminate, damaging the internal validity of an experiment by providing alternative explanations for outcomes.

Experimental Manipulation

The deliberate alteration of the independent variable in an experiment in order to learn about its effects on the dependent variable.

Control Groups

In experimental research, a group of subjects that does not receive the treatment being tested and is used as a benchmark to measure how the other tested subjects respond.