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Finding the Fourth Proportional to 77.48, 115.55 and 71.72

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Solution

The fourth proportional to 77.48, 115.55 and 71.72 is: 106.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.48 : 115.55 = 71.72 : x
  2. Step 2: Convert to fraction form
    77.48/115.55 = 71.72/x
  3. Step 3: Cross multiply
    77.48x = 115.55 × 71.72
  4. Step 4: Simplify right side
    77.48x = 8,286.58
  5. Step 5: Solve for x
    x = 8,286.58/77.48
  6. Step 6: Final answer
    x = 106.96

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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.