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Finding the Fourth Proportional to 208.82, 288.26 and 138.90

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Solution

The fourth proportional to 208.82, 288.26 and 138.90 is: 191.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.82 : 288.26 = 138.90 : x
  2. Step 2: Convert to fraction form
    208.82/288.26 = 138.90/x
  3. Step 3: Cross multiply
    208.82x = 288.26 × 138.90
  4. Step 4: Simplify right side
    208.82x = 40,039.31
  5. Step 5: Solve for x
    x = 40,039.31/208.82
  6. Step 6: Final answer
    x = 191.74

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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.