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Finding the Fourth Proportional to 208.69, 287.95 and 121.35

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Solution

The fourth proportional to 208.69, 287.95 and 121.35 is: 167.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.69 : 287.95 = 121.35 : x
  2. Step 2: Convert to fraction form
    208.69/287.95 = 121.35/x
  3. Step 3: Cross multiply
    208.69x = 287.95 × 121.35
  4. Step 4: Simplify right side
    208.69x = 34,942.73
  5. Step 5: Solve for x
    x = 34,942.73/208.69
  6. Step 6: Final answer
    x = 167.44

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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.