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Finding the Fourth Proportional to 691.87, 1,037.55 and 280.90

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Solution

The fourth proportional to 691.87, 1,037.55 and 280.90 is: 421.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    691.87 : 1,037.55 = 280.90 : x
  2. Step 2: Convert to fraction form
    691.87/1,037.55 = 280.90/x
  3. Step 3: Cross multiply
    691.87x = 1,037.55 × 280.90
  4. Step 4: Simplify right side
    691.87x = 291,447.80
  5. Step 5: Solve for x
    x = 291,447.80/691.87
  6. Step 6: Final answer
    x = 421.25

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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.