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Finding the Fourth Proportional to 77.68, 107.16 and 52.78

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Solution

The fourth proportional to 77.68, 107.16 and 52.78 is: 72.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.68 : 107.16 = 52.78 : x
  2. Step 2: Convert to fraction form
    77.68/107.16 = 52.78/x
  3. Step 3: Cross multiply
    77.68x = 107.16 × 52.78
  4. Step 4: Simplify right side
    77.68x = 5,655.90
  5. Step 5: Solve for x
    x = 5,655.90/77.68
  6. Step 6: Final answer
    x = 72.81

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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.