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Finding the Fourth Proportional to 208.68, 289.91 and 206.78

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Solution

The fourth proportional to 208.68, 289.91 and 206.78 is: 287.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.68 : 289.91 = 206.78 : x
  2. Step 2: Convert to fraction form
    208.68/289.91 = 206.78/x
  3. Step 3: Cross multiply
    208.68x = 289.91 × 206.78
  4. Step 4: Simplify right side
    208.68x = 59,947.59
  5. Step 5: Solve for x
    x = 59,947.59/208.68
  6. Step 6: Final answer
    x = 287.27

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.