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Finding the Fourth Proportional to 890.72, 1,229.12 and 517.80

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Solution

The fourth proportional to 890.72, 1,229.12 and 517.80 is: 714.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    890.72 : 1,229.12 = 517.80 : x
  2. Step 2: Convert to fraction form
    890.72/1,229.12 = 517.80/x
  3. Step 3: Cross multiply
    890.72x = 1,229.12 × 517.80
  4. Step 4: Simplify right side
    890.72x = 636,438.34
  5. Step 5: Solve for x
    x = 636,438.34/890.72
  6. Step 6: Final answer
    x = 714.52

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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.