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Finding the Fourth Proportional to 420.61, 580.45 and 254.80

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Solution

The fourth proportional to 420.61, 580.45 and 254.80 is: 351.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.61 : 580.45 = 254.80 : x
  2. Step 2: Convert to fraction form
    420.61/580.45 = 254.80/x
  3. Step 3: Cross multiply
    420.61x = 580.45 × 254.80
  4. Step 4: Simplify right side
    420.61x = 147,898.66
  5. Step 5: Solve for x
    x = 147,898.66/420.61
  6. Step 6: Final answer
    x = 351.63

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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.