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Finding the Fourth Proportional to 206.31, 309.61 and 115.08

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Solution

The fourth proportional to 206.31, 309.61 and 115.08 is: 172.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.31 : 309.61 = 115.08 : x
  2. Step 2: Convert to fraction form
    206.31/309.61 = 115.08/x
  3. Step 3: Cross multiply
    206.31x = 309.61 × 115.08
  4. Step 4: Simplify right side
    206.31x = 35,629.92
  5. Step 5: Solve for x
    x = 35,629.92/206.31
  6. Step 6: Final answer
    x = 172.70

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.