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Finding the Fourth Proportional to 709.70, 978.32 and 499.19

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Solution

The fourth proportional to 709.70, 978.32 and 499.19 is: 688.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    709.70 : 978.32 = 499.19 : x
  2. Step 2: Convert to fraction form
    709.70/978.32 = 499.19/x
  3. Step 3: Cross multiply
    709.70x = 978.32 × 499.19
  4. Step 4: Simplify right side
    709.70x = 488,363.92
  5. Step 5: Solve for x
    x = 488,363.92/709.70
  6. Step 6: Final answer
    x = 688.13

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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.