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Finding the Fourth Proportional to 717.96, 988.56 and 688.40

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Solution

The fourth proportional to 717.96, 988.56 and 688.40 is: 947.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    717.96 : 988.56 = 688.40 : x
  2. Step 2: Convert to fraction form
    717.96/988.56 = 688.40/x
  3. Step 3: Cross multiply
    717.96x = 988.56 × 688.40
  4. Step 4: Simplify right side
    717.96x = 680,524.70
  5. Step 5: Solve for x
    x = 680,524.70/717.96
  6. Step 6: Final answer
    x = 947.86

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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.