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Finding the Fourth Proportional to 421.60, 581.87 and 255.91

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Solution

The fourth proportional to 421.60, 581.87 and 255.91 is: 353.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.60 : 581.87 = 255.91 : x
  2. Step 2: Convert to fraction form
    421.60/581.87 = 255.91/x
  3. Step 3: Cross multiply
    421.60x = 581.87 × 255.91
  4. Step 4: Simplify right side
    421.60x = 148,906.35
  5. Step 5: Solve for x
    x = 148,906.35/421.60
  6. Step 6: Final answer
    x = 353.19

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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.