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Finding the Fourth Proportional to 208.28, 287.35 and 138.37

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Solution

The fourth proportional to 208.28, 287.35 and 138.37 is: 190.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.28 : 287.35 = 138.37 : x
  2. Step 2: Convert to fraction form
    208.28/287.35 = 138.37/x
  3. Step 3: Cross multiply
    208.28x = 287.35 × 138.37
  4. Step 4: Simplify right side
    208.28x = 39,760.62
  5. Step 5: Solve for x
    x = 39,760.62/208.28
  6. Step 6: Final answer
    x = 190.90

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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.