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Finding the Fourth Proportional to 89.80, 134.58 and 80.68

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Solution

The fourth proportional to 89.80, 134.58 and 80.68 is: 120.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    89.80 : 134.58 = 80.68 : x
  2. Step 2: Convert to fraction form
    89.80/134.58 = 80.68/x
  3. Step 3: Cross multiply
    89.80x = 134.58 × 80.68
  4. Step 4: Simplify right side
    89.80x = 10,857.91
  5. Step 5: Solve for x
    x = 10,857.91/89.80
  6. Step 6: Final answer
    x = 120.91

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.