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Finding the Fourth Proportional to 206.31, 309.47 and 120.75

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Solution

The fourth proportional to 206.31, 309.47 and 120.75 is: 181.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.31 : 309.47 = 120.75 : x
  2. Step 2: Convert to fraction form
    206.31/309.47 = 120.75/x
  3. Step 3: Cross multiply
    206.31x = 309.47 × 120.75
  4. Step 4: Simplify right side
    206.31x = 37,368.50
  5. Step 5: Solve for x
    x = 37,368.50/206.31
  6. Step 6: Final answer
    x = 181.13

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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.