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Finding the Fourth Proportional to 225.51, 311.21 and 138.20

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Solution

The fourth proportional to 225.51, 311.21 and 138.20 is: 190.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    225.51 : 311.21 = 138.20 : x
  2. Step 2: Convert to fraction form
    225.51/311.21 = 138.20/x
  3. Step 3: Cross multiply
    225.51x = 311.21 × 138.20
  4. Step 4: Simplify right side
    225.51x = 43,006.97
  5. Step 5: Solve for x
    x = 43,006.97/225.51
  6. Step 6: Final answer
    x = 190.71

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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.