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Finding the Fourth Proportional to 206.81, 309.85 and 121.13

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Solution

The fourth proportional to 206.81, 309.85 and 121.13 is: 181.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.81 : 309.85 = 121.13 : x
  2. Step 2: Convert to fraction form
    206.81/309.85 = 121.13/x
  3. Step 3: Cross multiply
    206.81x = 309.85 × 121.13
  4. Step 4: Simplify right side
    206.81x = 37,530.28
  5. Step 5: Solve for x
    x = 37,530.28/206.81
  6. Step 6: Final answer
    x = 181.48

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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.