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Finding the Fourth Proportional to 420.59, 581.13 and 405.80

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Solution

The fourth proportional to 420.59, 581.13 and 405.80 is: 560.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.59 : 581.13 = 405.80 : x
  2. Step 2: Convert to fraction form
    420.59/581.13 = 405.80/x
  3. Step 3: Cross multiply
    420.59x = 581.13 × 405.80
  4. Step 4: Simplify right side
    420.59x = 235,822.55
  5. Step 5: Solve for x
    x = 235,822.55/420.59
  6. Step 6: Final answer
    x = 560.69

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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.