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Finding the Fourth Proportional to 209.38, 315.46 and 206.86

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Solution

The fourth proportional to 209.38, 315.46 and 206.86 is: 311.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.38 : 315.46 = 206.86 : x
  2. Step 2: Convert to fraction form
    209.38/315.46 = 206.86/x
  3. Step 3: Cross multiply
    209.38x = 315.46 × 206.86
  4. Step 4: Simplify right side
    209.38x = 65,256.06
  5. Step 5: Solve for x
    x = 65,256.06/209.38
  6. Step 6: Final answer
    x = 311.66

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.