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Finding the Fourth Proportional to 420.37, 629.48 and 257.56

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Solution

The fourth proportional to 420.37, 629.48 and 257.56 is: 385.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.37 : 629.48 = 257.56 : x
  2. Step 2: Convert to fraction form
    420.37/629.48 = 257.56/x
  3. Step 3: Cross multiply
    420.37x = 629.48 × 257.56
  4. Step 4: Simplify right side
    420.37x = 162,127.58
  5. Step 5: Solve for x
    x = 162,127.58/420.37
  6. Step 6: Final answer
    x = 385.68

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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.