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Finding the Fourth Proportional to 517.60, 709.90 and 491.21

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Solution

The fourth proportional to 517.60, 709.90 and 491.21 is: 673.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    517.60 : 709.90 = 491.21 : x
  2. Step 2: Convert to fraction form
    517.60/709.90 = 491.21/x
  3. Step 3: Cross multiply
    517.60x = 709.90 × 491.21
  4. Step 4: Simplify right side
    517.60x = 348,709.98
  5. Step 5: Solve for x
    x = 348,709.98/517.60
  6. Step 6: Final answer
    x = 673.71

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.