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Finding the Fourth Proportional to 82.64, 113.38 and 78.56

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Solution

The fourth proportional to 82.64, 113.38 and 78.56 is: 107.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    82.64 : 113.38 = 78.56 : x
  2. Step 2: Convert to fraction form
    82.64/113.38 = 78.56/x
  3. Step 3: Cross multiply
    82.64x = 113.38 × 78.56
  4. Step 4: Simplify right side
    82.64x = 8,907.13
  5. Step 5: Solve for x
    x = 8,907.13/82.64
  6. Step 6: Final answer
    x = 107.78

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.