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Finding the Fourth Proportional to 664.92, 917.32 and 428.80

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Solution

The fourth proportional to 664.92, 917.32 and 428.80 is: 591.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    664.92 : 917.32 = 428.80 : x
  2. Step 2: Convert to fraction form
    664.92/917.32 = 428.80/x
  3. Step 3: Cross multiply
    664.92x = 917.32 × 428.80
  4. Step 4: Simplify right side
    664.92x = 393,346.82
  5. Step 5: Solve for x
    x = 393,346.82/664.92
  6. Step 6: Final answer
    x = 591.57

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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.