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Finding the Fourth Proportional to 142.21, 195.85 and 139.20

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Solution

The fourth proportional to 142.21, 195.85 and 139.20 is: 191.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.21 : 195.85 = 139.20 : x
  2. Step 2: Convert to fraction form
    142.21/195.85 = 139.20/x
  3. Step 3: Cross multiply
    142.21x = 195.85 × 139.20
  4. Step 4: Simplify right side
    142.21x = 27,262.32
  5. Step 5: Solve for x
    x = 27,262.32/142.21
  6. Step 6: Final answer
    x = 191.70

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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.