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Finding the Fourth Proportional to 420.85, 580.78 and 234.35

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Solution

The fourth proportional to 420.85, 580.78 and 234.35 is: 323.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.85 : 580.78 = 234.35 : x
  2. Step 2: Convert to fraction form
    420.85/580.78 = 234.35/x
  3. Step 3: Cross multiply
    420.85x = 580.78 × 234.35
  4. Step 4: Simplify right side
    420.85x = 136,105.79
  5. Step 5: Solve for x
    x = 136,105.79/420.85
  6. Step 6: Final answer
    x = 323.41

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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.