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Finding the Fourth Proportional to 81.76, 112.81 and 49

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Solution

The fourth proportional to 81.76, 112.81 and 49 is: 67.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.76 : 112.81 = 49 : x
  2. Step 2: Convert to fraction form
    81.76/112.81 = 49/x
  3. Step 3: Cross multiply
    81.76x = 112.81 × 49
  4. Step 4: Simplify right side
    81.76x = 5,527.69
  5. Step 5: Solve for x
    x = 5,527.69/81.76
  6. Step 6: Final answer
    x = 67.61

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.