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Finding the Fourth Proportional to 691.61, 1,036.85 and 280.94

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Solution

The fourth proportional to 691.61, 1,036.85 and 280.94 is: 421.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    691.61 : 1,036.85 = 280.94 : x
  2. Step 2: Convert to fraction form
    691.61/1,036.85 = 280.94/x
  3. Step 3: Cross multiply
    691.61x = 1,036.85 × 280.94
  4. Step 4: Simplify right side
    691.61x = 291,286.05
  5. Step 5: Solve for x
    x = 291,286.05/691.61
  6. Step 6: Final answer
    x = 421.17

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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.