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Finding the Fourth Proportional to 208.62, 287.85 and 138.60

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Solution

The fourth proportional to 208.62, 287.85 and 138.60 is: 191.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.62 : 287.85 = 138.60 : x
  2. Step 2: Convert to fraction form
    208.62/287.85 = 138.60/x
  3. Step 3: Cross multiply
    208.62x = 287.85 × 138.60
  4. Step 4: Simplify right side
    208.62x = 39,896.01
  5. Step 5: Solve for x
    x = 39,896.01/208.62
  6. Step 6: Final answer
    x = 191.24

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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.