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Finding the Fourth Proportional to 664.78, 917.31 and 431.50

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Solution

The fourth proportional to 664.78, 917.31 and 431.50 is: 595.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    664.78 : 917.31 = 431.50 : x
  2. Step 2: Convert to fraction form
    664.78/917.31 = 431.50/x
  3. Step 3: Cross multiply
    664.78x = 917.31 × 431.50
  4. Step 4: Simplify right side
    664.78x = 395,819.27
  5. Step 5: Solve for x
    x = 395,819.27/664.78
  6. Step 6: Final answer
    x = 595.41

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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.