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Finding the Fourth Proportional to 420.20, 629.76 and 203.48

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Solution

The fourth proportional to 420.20, 629.76 and 203.48 is: 304.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.20 : 629.76 = 203.48 : x
  2. Step 2: Convert to fraction form
    420.20/629.76 = 203.48/x
  3. Step 3: Cross multiply
    420.20x = 629.76 × 203.48
  4. Step 4: Simplify right side
    420.20x = 128,143.56
  5. Step 5: Solve for x
    x = 128,143.56/420.20
  6. Step 6: Final answer
    x = 304.96

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.