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Finding the Fourth Proportional to 77.32, 115.41 and 68.21

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Solution

The fourth proportional to 77.32, 115.41 and 68.21 is: 101.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.32 : 115.41 = 68.21 : x
  2. Step 2: Convert to fraction form
    77.32/115.41 = 68.21/x
  3. Step 3: Cross multiply
    77.32x = 115.41 × 68.21
  4. Step 4: Simplify right side
    77.32x = 7,871.54
  5. Step 5: Solve for x
    x = 7,871.54/77.32
  6. Step 6: Final answer
    x = 101.81

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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.