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Finding the Fourth Proportional to 89.76, 122.78 and 88.35

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Solution

The fourth proportional to 89.76, 122.78 and 88.35 is: 120.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    89.76 : 122.78 = 88.35 : x
  2. Step 2: Convert to fraction form
    89.76/122.78 = 88.35/x
  3. Step 3: Cross multiply
    89.76x = 122.78 × 88.35
  4. Step 4: Simplify right side
    89.76x = 10,847.17
  5. Step 5: Solve for x
    x = 10,847.17/89.76
  6. Step 6: Final answer
    x = 120.85

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.