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Finding the Fourth Proportional to 876.79, 1,314.09 and 487

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Solution

The fourth proportional to 876.79, 1,314.09 and 487 is: 729.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    876.79 : 1,314.09 = 487 : x
  2. Step 2: Convert to fraction form
    876.79/1,314.09 = 487/x
  3. Step 3: Cross multiply
    876.79x = 1,314.09 × 487
  4. Step 4: Simplify right side
    876.79x = 639,961.83
  5. Step 5: Solve for x
    x = 639,961.83/876.79
  6. Step 6: Final answer
    x = 729.89

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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.