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Finding the Fourth Proportional to 420.08, 629.42 and 257.41

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Solution

The fourth proportional to 420.08, 629.42 and 257.41 is: 385.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.08 : 629.42 = 257.41 : x
  2. Step 2: Convert to fraction form
    420.08/629.42 = 257.41/x
  3. Step 3: Cross multiply
    420.08x = 629.42 × 257.41
  4. Step 4: Simplify right side
    420.08x = 162,018.50
  5. Step 5: Solve for x
    x = 162,018.50/420.08
  6. Step 6: Final answer
    x = 385.69

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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.