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Finding the Fourth Proportional to 77.45, 115.91 and 67.42

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Solution

The fourth proportional to 77.45, 115.91 and 67.42 is: 100.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.45 : 115.91 = 67.42 : x
  2. Step 2: Convert to fraction form
    77.45/115.91 = 67.42/x
  3. Step 3: Cross multiply
    77.45x = 115.91 × 67.42
  4. Step 4: Simplify right side
    77.45x = 7,813.74
  5. Step 5: Solve for x
    x = 7,813.74/77.45
  6. Step 6: Final answer
    x = 100.89

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.