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Finding the Fourth Proportional to 81.10, 120.66 and 79.56

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Solution

The fourth proportional to 81.10, 120.66 and 79.56 is: 118.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.10 : 120.66 = 79.56 : x
  2. Step 2: Convert to fraction form
    81.10/120.66 = 79.56/x
  3. Step 3: Cross multiply
    81.10x = 120.66 × 79.56
  4. Step 4: Simplify right side
    81.10x = 9,599.41
  5. Step 5: Solve for x
    x = 9,599.41/81.10
  6. Step 6: Final answer
    x = 118.36

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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.