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Finding the Fourth Proportional to 318.85, 439.81 and 206.76

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Solution

The fourth proportional to 318.85, 439.81 and 206.76 is: 285.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.85 : 439.81 = 206.76 : x
  2. Step 2: Convert to fraction form
    318.85/439.81 = 206.76/x
  3. Step 3: Cross multiply
    318.85x = 439.81 × 206.76
  4. Step 4: Simplify right side
    318.85x = 90,935.12
  5. Step 5: Solve for x
    x = 90,935.12/318.85
  6. Step 6: Final answer
    x = 285.20

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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.