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Finding the Fourth Proportional to 691.45, 1,037.35 and 280.49

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Solution

The fourth proportional to 691.45, 1,037.35 and 280.49 is: 420.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    691.45 : 1,037.35 = 280.49 : x
  2. Step 2: Convert to fraction form
    691.45/1,037.35 = 280.49/x
  3. Step 3: Cross multiply
    691.45x = 1,037.35 × 280.49
  4. Step 4: Simplify right side
    691.45x = 290,966.30
  5. Step 5: Solve for x
    x = 290,966.30/691.45
  6. Step 6: Final answer
    x = 420.81

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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.