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Finding the Fourth Proportional to 138.00, 189.93 and 121.08

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Solution

The fourth proportional to 138.00, 189.93 and 121.08 is: 166.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.00 : 189.93 = 121.08 : x
  2. Step 2: Convert to fraction form
    138.00/189.93 = 121.08/x
  3. Step 3: Cross multiply
    138.00x = 189.93 × 121.08
  4. Step 4: Simplify right side
    138.00x = 22,996.14
  5. Step 5: Solve for x
    x = 22,996.14/138.00
  6. Step 6: Final answer
    x = 166.63

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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.