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Finding the Fourth Proportional to 781.88, 1,079.50 and 487.58

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Solution

The fourth proportional to 781.88, 1,079.50 and 487.58 is: 673.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.88 : 1,079.50 = 487.58 : x
  2. Step 2: Convert to fraction form
    781.88/1,079.50 = 487.58/x
  3. Step 3: Cross multiply
    781.88x = 1,079.50 × 487.58
  4. Step 4: Simplify right side
    781.88x = 526,342.61
  5. Step 5: Solve for x
    x = 526,342.61/781.88
  6. Step 6: Final answer
    x = 673.18

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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.