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Finding the Fourth Proportional to 429.74, 644.78 and 256.49

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Solution

The fourth proportional to 429.74, 644.78 and 256.49 is: 384.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.74 : 644.78 = 256.49 : x
  2. Step 2: Convert to fraction form
    429.74/644.78 = 256.49/x
  3. Step 3: Cross multiply
    429.74x = 644.78 × 256.49
  4. Step 4: Simplify right side
    429.74x = 165,379.62
  5. Step 5: Solve for x
    x = 165,379.62/429.74
  6. Step 6: Final answer
    x = 384.84

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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.