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Finding the Fourth Proportional to 765.88, 1,057.15 and 489.88

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Solution

The fourth proportional to 765.88, 1,057.15 and 489.88 is: 676.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    765.88 : 1,057.15 = 489.88 : x
  2. Step 2: Convert to fraction form
    765.88/1,057.15 = 489.88/x
  3. Step 3: Cross multiply
    765.88x = 1,057.15 × 489.88
  4. Step 4: Simplify right side
    765.88x = 517,876.64
  5. Step 5: Solve for x
    x = 517,876.64/765.88
  6. Step 6: Final answer
    x = 676.19

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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.