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Finding the Fourth Proportional to 399.43, 550.45 and 288.70

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Solution

The fourth proportional to 399.43, 550.45 and 288.70 is: 397.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.43 : 550.45 = 288.70 : x
  2. Step 2: Convert to fraction form
    399.43/550.45 = 288.70/x
  3. Step 3: Cross multiply
    399.43x = 550.45 × 288.70
  4. Step 4: Simplify right side
    399.43x = 158,914.92
  5. Step 5: Solve for x
    x = 158,914.92/399.43
  6. Step 6: Final answer
    x = 397.85

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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.