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Finding the Fourth Proportional to 688.80, 949.18 and 491.76

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Solution

The fourth proportional to 688.80, 949.18 and 491.76 is: 677.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.80 : 949.18 = 491.76 : x
  2. Step 2: Convert to fraction form
    688.80/949.18 = 491.76/x
  3. Step 3: Cross multiply
    688.80x = 949.18 × 491.76
  4. Step 4: Simplify right side
    688.80x = 466,768.76
  5. Step 5: Solve for x
    x = 466,768.76/688.80
  6. Step 6: Final answer
    x = 677.65

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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.