What is the common ratio of the geometric sequence 768, …

Mathematics Questions

what is the common ratio for the geometric sequence below, written as a fraction? 768, 480, 300, 187.5, …

Short Answer

The common ratio in the geometric sequence from a1 to a4 is determined to be frac{5}{8}, calculated through the ratios a2 to a1, a3 to a2, and a4 to a3, with each step simplifying to the same ratio.

Step-by-Step Solution

Step 1: Calculate the Ratio of a2 to a1

Begin by finding the ratio of a2 to a1. This is calculated as follows:

  • Apply the formula: frac{a2}{a1} = frac{480}{768}.
  • Simplify the fraction by dividing both the numerator and the denominator by 96: frac{480}{768} = frac{5}{8}.
  • Use the ratio to express a2 in terms of a1: a2 = a1 * frac{5}{8}.

Step 2: Calculate the Ratio of a3 to a2

Next, find the ratio of a3 to a2 using a similar process:

  • Apply the formula: frac{a3}{a2} = frac{300}{480}.
  • Simplify this fraction by dividing both parts by 60: frac{300}{480} = frac{5}{8}.
  • Express a3 in terms of a2: a3 = a2 * frac{5}{8}.

Step 3: Calculate the Ratio of a4 to a3

Finally, determine the ratio of a4 to a3 to complete the sequence:

  • First, recognize a4 as 187.5 or frac{375}{2}.
  • Calculate the ratio: frac{a4}{a3} = frac{frac{375}{2}}{300}, which simplifies to frac{375}{600}.
  • Simplify this ratio by dividing by 75: frac{375}{600} = frac{5}{8}.
  • Finally, express a4 in terms of a3: a4 = a3 * frac{5}{8}.

In conclusion, the common ratio in this geometric sequence is frac{5}{8}.

Related Concepts

Ratio

A ratio is a relationship between two quantities, indicating how many times one value contains or is contained within the other.

Simplification

Simplification is the process of reducing a fraction or equation to its simplest form by dividing the numerator and denominator by their greatest common divisor.

Geometric Sequence

A geometric sequence is a sequence of numbers where each term after the first is found by multiplying the previous term by a fixed, non-zero number called the common ratio.

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