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Finding the Fourth Proportional to 420.46, 580.21 and 243.39

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Solution

The fourth proportional to 420.46, 580.21 and 243.39 is: 335.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.46 : 580.21 = 243.39 : x
  2. Step 2: Convert to fraction form
    420.46/580.21 = 243.39/x
  3. Step 3: Cross multiply
    420.46x = 580.21 × 243.39
  4. Step 4: Simplify right side
    420.46x = 141,217.31
  5. Step 5: Solve for x
    x = 141,217.31/420.46
  6. Step 6: Final answer
    x = 335.86

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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.