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Finding the Fourth Proportional to 399.28, 550.44 and 355.56

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Solution

The fourth proportional to 399.28, 550.44 and 355.56 is: 490.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.28 : 550.44 = 355.56 : x
  2. Step 2: Convert to fraction form
    399.28/550.44 = 355.56/x
  3. Step 3: Cross multiply
    399.28x = 550.44 × 355.56
  4. Step 4: Simplify right side
    399.28x = 195,714.45
  5. Step 5: Solve for x
    x = 195,714.45/399.28
  6. Step 6: Final answer
    x = 490.17

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.