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Finding the Fourth Proportional to 420.72, 580.55 and 254.98

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Solution

The fourth proportional to 420.72, 580.55 and 254.98 is: 351.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.72 : 580.55 = 254.98 : x
  2. Step 2: Convert to fraction form
    420.72/580.55 = 254.98/x
  3. Step 3: Cross multiply
    420.72x = 580.55 × 254.98
  4. Step 4: Simplify right side
    420.72x = 148,024.46
  5. Step 5: Solve for x
    x = 148,024.46/420.72
  6. Step 6: Final answer
    x = 351.84

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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.