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Finding the Fourth Proportional to 225.70, 311.40 and 138.40

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Solution

The fourth proportional to 225.70, 311.40 and 138.40 is: 190.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    225.70 : 311.40 = 138.40 : x
  2. Step 2: Convert to fraction form
    225.70/311.40 = 138.40/x
  3. Step 3: Cross multiply
    225.70x = 311.40 × 138.40
  4. Step 4: Simplify right side
    225.70x = 43,097.76
  5. Step 5: Solve for x
    x = 43,097.76/225.70
  6. Step 6: Final answer
    x = 190.95

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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.