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Finding the Fourth Proportional to 208.60, 287.97 and 138.77

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Solution

The fourth proportional to 208.60, 287.97 and 138.77 is: 191.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.60 : 287.97 = 138.77 : x
  2. Step 2: Convert to fraction form
    208.60/287.97 = 138.77/x
  3. Step 3: Cross multiply
    208.60x = 287.97 × 138.77
  4. Step 4: Simplify right side
    208.60x = 39,961.62
  5. Step 5: Solve for x
    x = 39,961.62/208.60
  6. Step 6: Final answer
    x = 191.57

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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.