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Finding the Fourth Proportional to 142.78, 197.60 and 139.37

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Solution

The fourth proportional to 142.78, 197.60 and 139.37 is: 192.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.78 : 197.60 = 139.37 : x
  2. Step 2: Convert to fraction form
    142.78/197.60 = 139.37/x
  3. Step 3: Cross multiply
    142.78x = 197.60 × 139.37
  4. Step 4: Simplify right side
    142.78x = 27,539.51
  5. Step 5: Solve for x
    x = 27,539.51/142.78
  6. Step 6: Final answer
    x = 192.88

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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.