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Finding the Fourth Proportional to 89.06, 122.78 and 76.91

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Solution

The fourth proportional to 89.06, 122.78 and 76.91 is: 106.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    89.06 : 122.78 = 76.91 : x
  2. Step 2: Convert to fraction form
    89.06/122.78 = 76.91/x
  3. Step 3: Cross multiply
    89.06x = 122.78 × 76.91
  4. Step 4: Simplify right side
    89.06x = 9,442.59
  5. Step 5: Solve for x
    x = 9,442.59/89.06
  6. Step 6: Final answer
    x = 106.03

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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.