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Finding the Fourth Proportional to 77.80, 108.11 and 77.48

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Solution

The fourth proportional to 77.80, 108.11 and 77.48 is: 107.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.80 : 108.11 = 77.48 : x
  2. Step 2: Convert to fraction form
    77.80/108.11 = 77.48/x
  3. Step 3: Cross multiply
    77.80x = 108.11 × 77.48
  4. Step 4: Simplify right side
    77.80x = 8,376.36
  5. Step 5: Solve for x
    x = 8,376.36/77.80
  6. Step 6: Final answer
    x = 107.67

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.