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Finding the Fourth Proportional to 418.88, 628.44 and 256.76

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Solution

The fourth proportional to 418.88, 628.44 and 256.76 is: 385.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    418.88 : 628.44 = 256.76 : x
  2. Step 2: Convert to fraction form
    418.88/628.44 = 256.76/x
  3. Step 3: Cross multiply
    418.88x = 628.44 × 256.76
  4. Step 4: Simplify right side
    418.88x = 161,358.25
  5. Step 5: Solve for x
    x = 161,358.25/418.88
  6. Step 6: Final answer
    x = 385.21

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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.