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Finding the Fourth Proportional to 429.74, 645.06 and 256.61

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Solution

The fourth proportional to 429.74, 645.06 and 256.61 is: 385.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.74 : 645.06 = 256.61 : x
  2. Step 2: Convert to fraction form
    429.74/645.06 = 256.61/x
  3. Step 3: Cross multiply
    429.74x = 645.06 × 256.61
  4. Step 4: Simplify right side
    429.74x = 165,525.62
  5. Step 5: Solve for x
    x = 165,525.62/429.74
  6. Step 6: Final answer
    x = 385.18

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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.