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Finding the Fourth Proportional to 92.81, 128 and 81.14

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Solution

The fourth proportional to 92.81, 128 and 81.14 is: 111.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    92.81 : 128 = 81.14 : x
  2. Step 2: Convert to fraction form
    92.81/128 = 81.14/x
  3. Step 3: Cross multiply
    92.81x = 128 × 81.14
  4. Step 4: Simplify right side
    92.81x = 10,385.92
  5. Step 5: Solve for x
    x = 10,385.92/92.81
  6. Step 6: Final answer
    x = 111.91

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