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Finding the Fourth Proportional to 420.10, 629.24 and 257.29

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Solution

The fourth proportional to 420.10, 629.24 and 257.29 is: 385.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.10 : 629.24 = 257.29 : x
  2. Step 2: Convert to fraction form
    420.10/629.24 = 257.29/x
  3. Step 3: Cross multiply
    420.10x = 629.24 × 257.29
  4. Step 4: Simplify right side
    420.10x = 161,897.16
  5. Step 5: Solve for x
    x = 161,897.16/420.10
  6. Step 6: Final answer
    x = 385.38

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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.