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Finding the Fourth Proportional to 645.20, 890.01 and 408.71

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Solution

The fourth proportional to 645.20, 890.01 and 408.71 is: 563.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.20 : 890.01 = 408.71 : x
  2. Step 2: Convert to fraction form
    645.20/890.01 = 408.71/x
  3. Step 3: Cross multiply
    645.20x = 890.01 × 408.71
  4. Step 4: Simplify right side
    645.20x = 363,751.54
  5. Step 5: Solve for x
    x = 363,751.54/645.20
  6. Step 6: Final answer
    x = 563.79

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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.