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Finding the Fourth Proportional to 691.20, 1,036.92 and 306.72

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Solution

The fourth proportional to 691.20, 1,036.92 and 306.72 is: 460.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    691.20 : 1,036.92 = 306.72 : x
  2. Step 2: Convert to fraction form
    691.20/1,036.92 = 306.72/x
  3. Step 3: Cross multiply
    691.20x = 1,036.92 × 306.72
  4. Step 4: Simplify right side
    691.20x = 318,044.10
  5. Step 5: Solve for x
    x = 318,044.10/691.20
  6. Step 6: Final answer
    x = 460.13

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.