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Finding the Fourth Proportional to 420.57, 629.78 and 203.63

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Solution

The fourth proportional to 420.57, 629.78 and 203.63 is: 304.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.57 : 629.78 = 203.63 : x
  2. Step 2: Convert to fraction form
    420.57/629.78 = 203.63/x
  3. Step 3: Cross multiply
    420.57x = 629.78 × 203.63
  4. Step 4: Simplify right side
    420.57x = 128,237.93
  5. Step 5: Solve for x
    x = 128,237.93/420.57
  6. Step 6: Final answer
    x = 304.91

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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.