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Finding the Fourth Proportional to 260.54, 390.43 and 138.90

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Solution

The fourth proportional to 260.54, 390.43 and 138.90 is: 208.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    260.54 : 390.43 = 138.90 : x
  2. Step 2: Convert to fraction form
    260.54/390.43 = 138.90/x
  3. Step 3: Cross multiply
    260.54x = 390.43 × 138.90
  4. Step 4: Simplify right side
    260.54x = 54,230.73
  5. Step 5: Solve for x
    x = 54,230.73/260.54
  6. Step 6: Final answer
    x = 208.15

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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.