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Finding the Fourth Proportional to 430.85, 644.67 and 257.61

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Solution

The fourth proportional to 430.85, 644.67 and 257.61 is: 385.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.85 : 644.67 = 257.61 : x
  2. Step 2: Convert to fraction form
    430.85/644.67 = 257.61/x
  3. Step 3: Cross multiply
    430.85x = 644.67 × 257.61
  4. Step 4: Simplify right side
    430.85x = 166,073.44
  5. Step 5: Solve for x
    x = 166,073.44/430.85
  6. Step 6: Final answer
    x = 385.46

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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.