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Finding the Fourth Proportional to 142.39, 196.45 and 80.21

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Solution

The fourth proportional to 142.39, 196.45 and 80.21 is: 110.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.39 : 196.45 = 80.21 : x
  2. Step 2: Convert to fraction form
    142.39/196.45 = 80.21/x
  3. Step 3: Cross multiply
    142.39x = 196.45 × 80.21
  4. Step 4: Simplify right side
    142.39x = 15,757.75
  5. Step 5: Solve for x
    x = 15,757.75/142.39
  6. Step 6: Final answer
    x = 110.67

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.