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Finding the Fourth Proportional to 77.65, 107.10 and 55.78

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Solution

The fourth proportional to 77.65, 107.10 and 55.78 is: 76.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.65 : 107.10 = 55.78 : x
  2. Step 2: Convert to fraction form
    77.65/107.10 = 55.78/x
  3. Step 3: Cross multiply
    77.65x = 107.10 × 55.78
  4. Step 4: Simplify right side
    77.65x = 5,974.04
  5. Step 5: Solve for x
    x = 5,974.04/77.65
  6. Step 6: Final answer
    x = 76.94

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.