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Finding the Fourth Proportional to 209.20, 312.14 and 207.86

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Solution

The fourth proportional to 209.20, 312.14 and 207.86 is: 310.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.20 : 312.14 = 207.86 : x
  2. Step 2: Convert to fraction form
    209.20/312.14 = 207.86/x
  3. Step 3: Cross multiply
    209.20x = 312.14 × 207.86
  4. Step 4: Simplify right side
    209.20x = 64,881.42
  5. Step 5: Solve for x
    x = 64,881.42/209.20
  6. Step 6: Final answer
    x = 310.14

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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.