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Finding the Fourth Proportional to 205.91, 308.68 and 77.75

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Solution

The fourth proportional to 205.91, 308.68 and 77.75 is: 116.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    205.91 : 308.68 = 77.75 : x
  2. Step 2: Convert to fraction form
    205.91/308.68 = 77.75/x
  3. Step 3: Cross multiply
    205.91x = 308.68 × 77.75
  4. Step 4: Simplify right side
    205.91x = 23,997.94
  5. Step 5: Solve for x
    x = 23,997.94/205.91
  6. Step 6: Final answer
    x = 116.55

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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.