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Finding the Fourth Proportional to 138.24, 190.81 and 89.25

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Solution

The fourth proportional to 138.24, 190.81 and 89.25 is: 123.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.24 : 190.81 = 89.25 : x
  2. Step 2: Convert to fraction form
    138.24/190.81 = 89.25/x
  3. Step 3: Cross multiply
    138.24x = 190.81 × 89.25
  4. Step 4: Simplify right side
    138.24x = 17,029.79
  5. Step 5: Solve for x
    x = 17,029.79/138.24
  6. Step 6: Final answer
    x = 123.19

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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.