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Finding the Fourth Proportional to 142.31, 211.94 and 139.28

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Solution

The fourth proportional to 142.31, 211.94 and 139.28 is: 207.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.31 : 211.94 = 139.28 : x
  2. Step 2: Convert to fraction form
    142.31/211.94 = 139.28/x
  3. Step 3: Cross multiply
    142.31x = 211.94 × 139.28
  4. Step 4: Simplify right side
    142.31x = 29,517.25
  5. Step 5: Solve for x
    x = 29,517.25/142.31
  6. Step 6: Final answer
    x = 207.41

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.