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Finding the Fourth Proportional to 509.85, 702.90 and 398.88

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Solution

The fourth proportional to 509.85, 702.90 and 398.88 is: 549.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    509.85 : 702.90 = 398.88 : x
  2. Step 2: Convert to fraction form
    509.85/702.90 = 398.88/x
  3. Step 3: Cross multiply
    509.85x = 702.90 × 398.88
  4. Step 4: Simplify right side
    509.85x = 280,372.75
  5. Step 5: Solve for x
    x = 280,372.75/509.85
  6. Step 6: Final answer
    x = 549.91

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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.