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Finding the Fourth Proportional to 189.70, 284.69 and 81.57

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Solution

The fourth proportional to 189.70, 284.69 and 81.57 is: 122.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    189.70 : 284.69 = 81.57 : x
  2. Step 2: Convert to fraction form
    189.70/284.69 = 81.57/x
  3. Step 3: Cross multiply
    189.70x = 284.69 × 81.57
  4. Step 4: Simplify right side
    189.70x = 23,222.16
  5. Step 5: Solve for x
    x = 23,222.16/189.70
  6. Step 6: Final answer
    x = 122.42

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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.