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Finding the Fourth Proportional to 77.70, 115.85 and 77.07

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Solution

The fourth proportional to 77.70, 115.85 and 77.07 is: 114.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.70 : 115.85 = 77.07 : x
  2. Step 2: Convert to fraction form
    77.70/115.85 = 77.07/x
  3. Step 3: Cross multiply
    77.70x = 115.85 × 77.07
  4. Step 4: Simplify right side
    77.70x = 8,928.17
  5. Step 5: Solve for x
    x = 8,928.17/77.70
  6. Step 6: Final answer
    x = 114.91

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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.