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Finding the Fourth Proportional to 77.30, 115.79 and 41.21

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Solution

The fourth proportional to 77.30, 115.79 and 41.21 is: 61.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.30 : 115.79 = 41.21 : x
  2. Step 2: Convert to fraction form
    77.30/115.79 = 41.21/x
  3. Step 3: Cross multiply
    77.30x = 115.79 × 41.21
  4. Step 4: Simplify right side
    77.30x = 4,770.92
  5. Step 5: Solve for x
    x = 4,770.92/77.30
  6. Step 6: Final answer
    x = 61.72

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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.