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Finding the Fourth Proportional to 691.72, 1,037.55 and 280.74

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Solution

The fourth proportional to 691.72, 1,037.55 and 280.74 is: 421.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    691.72 : 1,037.55 = 280.74 : x
  2. Step 2: Convert to fraction form
    691.72/1,037.55 = 280.74/x
  3. Step 3: Cross multiply
    691.72x = 1,037.55 × 280.74
  4. Step 4: Simplify right side
    691.72x = 291,281.79
  5. Step 5: Solve for x
    x = 291,281.79/691.72
  6. Step 6: Final answer
    x = 421.10

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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.