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Finding the Fourth Proportional to 300.70, 451.20 and 138.50

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Solution

The fourth proportional to 300.70, 451.20 and 138.50 is: 207.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    300.70 : 451.20 = 138.50 : x
  2. Step 2: Convert to fraction form
    300.70/451.20 = 138.50/x
  3. Step 3: Cross multiply
    300.70x = 451.20 × 138.50
  4. Step 4: Simplify right side
    300.70x = 62,491.20
  5. Step 5: Solve for x
    x = 62,491.20/300.70
  6. Step 6: Final answer
    x = 207.82

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.