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Finding the Fourth Proportional to 418.28, 579.96 and 396.40

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Solution

The fourth proportional to 418.28, 579.96 and 396.40 is: 549.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    418.28 : 579.96 = 396.40 : x
  2. Step 2: Convert to fraction form
    418.28/579.96 = 396.40/x
  3. Step 3: Cross multiply
    418.28x = 579.96 × 396.40
  4. Step 4: Simplify right side
    418.28x = 229,896.14
  5. Step 5: Solve for x
    x = 229,896.14/418.28
  6. Step 6: Final answer
    x = 549.62

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.