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Finding the Fourth Proportional to 398.84, 549.72 and 280.85

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Solution

The fourth proportional to 398.84, 549.72 and 280.85 is: 387.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.84 : 549.72 = 280.85 : x
  2. Step 2: Convert to fraction form
    398.84/549.72 = 280.85/x
  3. Step 3: Cross multiply
    398.84x = 549.72 × 280.85
  4. Step 4: Simplify right side
    398.84x = 154,388.86
  5. Step 5: Solve for x
    x = 154,388.86/398.84
  6. Step 6: Final answer
    x = 387.09

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.