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Finding the Fourth Proportional to 208.86, 288.09 and 121.47

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Solution

The fourth proportional to 208.86, 288.09 and 121.47 is: 167.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.86 : 288.09 = 121.47 : x
  2. Step 2: Convert to fraction form
    208.86/288.09 = 121.47/x
  3. Step 3: Cross multiply
    208.86x = 288.09 × 121.47
  4. Step 4: Simplify right side
    208.86x = 34,994.29
  5. Step 5: Solve for x
    x = 34,994.29/208.86
  6. Step 6: Final answer
    x = 167.55

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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.