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Finding the Fourth Proportional to 429.49, 644.31 and 256.30

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Solution

The fourth proportional to 429.49, 644.31 and 256.30 is: 384.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.49 : 644.31 = 256.30 : x
  2. Step 2: Convert to fraction form
    429.49/644.31 = 256.30/x
  3. Step 3: Cross multiply
    429.49x = 644.31 × 256.30
  4. Step 4: Simplify right side
    429.49x = 165,136.65
  5. Step 5: Solve for x
    x = 165,136.65/429.49
  6. Step 6: Final answer
    x = 384.49

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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.