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Finding the Fourth Proportional to 664.31, 917.18 and 428.36

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Solution

The fourth proportional to 664.31, 917.18 and 428.36 is: 591.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    664.31 : 917.18 = 428.36 : x
  2. Step 2: Convert to fraction form
    664.31/917.18 = 428.36/x
  3. Step 3: Cross multiply
    664.31x = 917.18 × 428.36
  4. Step 4: Simplify right side
    664.31x = 392,876.50
  5. Step 5: Solve for x
    x = 392,876.50/664.31
  6. Step 6: Final answer
    x = 591.41

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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.