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Finding the Fourth Proportional to 81.05, 111.80 and 55.13

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Solution

The fourth proportional to 81.05, 111.80 and 55.13 is: 76.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.05 : 111.80 = 55.13 : x
  2. Step 2: Convert to fraction form
    81.05/111.80 = 55.13/x
  3. Step 3: Cross multiply
    81.05x = 111.80 × 55.13
  4. Step 4: Simplify right side
    81.05x = 6,162.70
  5. Step 5: Solve for x
    x = 6,162.70/81.05
  6. Step 6: Final answer
    x = 76.04

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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.