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Finding the Fourth Proportional to 77.70, 115.99 and 72.07

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Solution

The fourth proportional to 77.70, 115.99 and 72.07 is: 107.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.70 : 115.99 = 72.07 : x
  2. Step 2: Convert to fraction form
    77.70/115.99 = 72.07/x
  3. Step 3: Cross multiply
    77.70x = 115.99 × 72.07
  4. Step 4: Simplify right side
    77.70x = 8,359.58
  5. Step 5: Solve for x
    x = 8,359.58/77.70
  6. Step 6: Final answer
    x = 107.58

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.