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Finding the Fourth Proportional to 430.72, 644.49 and 257.48

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Solution

The fourth proportional to 430.72, 644.49 and 257.48 is: 385.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.72 : 644.49 = 257.48 : x
  2. Step 2: Convert to fraction form
    430.72/644.49 = 257.48/x
  3. Step 3: Cross multiply
    430.72x = 644.49 × 257.48
  4. Step 4: Simplify right side
    430.72x = 165,942.00
  5. Step 5: Solve for x
    x = 165,942.00/430.72
  6. Step 6: Final answer
    x = 385.27

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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.