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Finding the Fourth Proportional to 89.39, 122.56 and 87.77

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Solution

The fourth proportional to 89.39, 122.56 and 87.77 is: 120.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    89.39 : 122.56 = 87.77 : x
  2. Step 2: Convert to fraction form
    89.39/122.56 = 87.77/x
  3. Step 3: Cross multiply
    89.39x = 122.56 × 87.77
  4. Step 4: Simplify right side
    89.39x = 10,756.65
  5. Step 5: Solve for x
    x = 10,756.65/89.39
  6. Step 6: Final answer
    x = 120.33

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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.