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Finding the Fourth Proportional to 89.32, 122.12 and 86.80

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Solution

The fourth proportional to 89.32, 122.12 and 86.80 is: 118.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    89.32 : 122.12 = 86.80 : x
  2. Step 2: Convert to fraction form
    89.32/122.12 = 86.80/x
  3. Step 3: Cross multiply
    89.32x = 122.12 × 86.80
  4. Step 4: Simplify right side
    89.32x = 10,600.02
  5. Step 5: Solve for x
    x = 10,600.02/89.32
  6. Step 6: Final answer
    x = 118.67

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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.