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Finding the Fourth Proportional to 420.98, 580.44 and 355.34

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Solution

The fourth proportional to 420.98, 580.44 and 355.34 is: 489.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.98 : 580.44 = 355.34 : x
  2. Step 2: Convert to fraction form
    420.98/580.44 = 355.34/x
  3. Step 3: Cross multiply
    420.98x = 580.44 × 355.34
  4. Step 4: Simplify right side
    420.98x = 206,253.55
  5. Step 5: Solve for x
    x = 206,253.55/420.98
  6. Step 6: Final answer
    x = 489.94

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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.