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Finding the Fourth Proportional to 260.75, 391.18 and 138.98

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Solution

The fourth proportional to 260.75, 391.18 and 138.98 is: 208.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    260.75 : 391.18 = 138.98 : x
  2. Step 2: Convert to fraction form
    260.75/391.18 = 138.98/x
  3. Step 3: Cross multiply
    260.75x = 391.18 × 138.98
  4. Step 4: Simplify right side
    260.75x = 54,366.20
  5. Step 5: Solve for x
    x = 54,366.20/260.75
  6. Step 6: Final answer
    x = 208.50

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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.