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Finding the Fourth Proportional to 470.09, 648.90 and 420.87

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Solution

The fourth proportional to 470.09, 648.90 and 420.87 is: 580.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    470.09 : 648.90 = 420.87 : x
  2. Step 2: Convert to fraction form
    470.09/648.90 = 420.87/x
  3. Step 3: Cross multiply
    470.09x = 648.90 × 420.87
  4. Step 4: Simplify right side
    470.09x = 273,102.54
  5. Step 5: Solve for x
    x = 273,102.54/470.09
  6. Step 6: Final answer
    x = 580.96

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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.