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Finding the Fourth Proportional to 139.21, 192.17 and 90.14

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Solution

The fourth proportional to 139.21, 192.17 and 90.14 is: 124.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.21 : 192.17 = 90.14 : x
  2. Step 2: Convert to fraction form
    139.21/192.17 = 90.14/x
  3. Step 3: Cross multiply
    139.21x = 192.17 × 90.14
  4. Step 4: Simplify right side
    139.21x = 17,321.47
  5. Step 5: Solve for x
    x = 17,321.47/139.21
  6. Step 6: Final answer
    x = 124.43

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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.