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Finding the Fourth Proportional to 213.87, 318.27 and 209.61

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Solution

The fourth proportional to 213.87, 318.27 and 209.61 is: 311.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    213.87 : 318.27 = 209.61 : x
  2. Step 2: Convert to fraction form
    213.87/318.27 = 209.61/x
  3. Step 3: Cross multiply
    213.87x = 318.27 × 209.61
  4. Step 4: Simplify right side
    213.87x = 66,712.57
  5. Step 5: Solve for x
    x = 66,712.57/213.87
  6. Step 6: Final answer
    x = 311.93

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.