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Finding the Fourth Proportional to 664.91, 917.08 and 428.71

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Solution

The fourth proportional to 664.91, 917.08 and 428.71 is: 591.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    664.91 : 917.08 = 428.71 : x
  2. Step 2: Convert to fraction form
    664.91/917.08 = 428.71/x
  3. Step 3: Cross multiply
    664.91x = 917.08 × 428.71
  4. Step 4: Simplify right side
    664.91x = 393,161.37
  5. Step 5: Solve for x
    x = 393,161.37/664.91
  6. Step 6: Final answer
    x = 591.30

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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.