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Finding the Fourth Proportional to 429.59, 644.34 and 257.47

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Solution

The fourth proportional to 429.59, 644.34 and 257.47 is: 386.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.59 : 644.34 = 257.47 : x
  2. Step 2: Convert to fraction form
    429.59/644.34 = 257.47/x
  3. Step 3: Cross multiply
    429.59x = 644.34 × 257.47
  4. Step 4: Simplify right side
    429.59x = 165,898.22
  5. Step 5: Solve for x
    x = 165,898.22/429.59
  6. Step 6: Final answer
    x = 386.18

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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.