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Finding the Fourth Proportional to 418.56, 628.14 and 279.90

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Solution

The fourth proportional to 418.56, 628.14 and 279.90 is: 420.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    418.56 : 628.14 = 279.90 : x
  2. Step 2: Convert to fraction form
    418.56/628.14 = 279.90/x
  3. Step 3: Cross multiply
    418.56x = 628.14 × 279.90
  4. Step 4: Simplify right side
    418.56x = 175,816.39
  5. Step 5: Solve for x
    x = 175,816.39/418.56
  6. Step 6: Final answer
    x = 420.05

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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.