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Finding the Fourth Proportional to 260.91, 390.92 and 139.05

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Solution

The fourth proportional to 260.91, 390.92 and 139.05 is: 208.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    260.91 : 390.92 = 139.05 : x
  2. Step 2: Convert to fraction form
    260.91/390.92 = 139.05/x
  3. Step 3: Cross multiply
    260.91x = 390.92 × 139.05
  4. Step 4: Simplify right side
    260.91x = 54,356.73
  5. Step 5: Solve for x
    x = 54,356.73/260.91
  6. Step 6: Final answer
    x = 208.34

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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.