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Finding the Fourth Proportional to 318.21, 439.20 and 207.87

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Solution

The fourth proportional to 318.21, 439.20 and 207.87 is: 286.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.21 : 439.20 = 207.87 : x
  2. Step 2: Convert to fraction form
    318.21/439.20 = 207.87/x
  3. Step 3: Cross multiply
    318.21x = 439.20 × 207.87
  4. Step 4: Simplify right side
    318.21x = 91,296.50
  5. Step 5: Solve for x
    x = 91,296.50/318.21
  6. Step 6: Final answer
    x = 286.91

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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.