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Finding the Fourth Proportional to 208.89, 288.39 and 139.05

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Solution

The fourth proportional to 208.89, 288.39 and 139.05 is: 191.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.89 : 288.39 = 139.05 : x
  2. Step 2: Convert to fraction form
    208.89/288.39 = 139.05/x
  3. Step 3: Cross multiply
    208.89x = 288.39 × 139.05
  4. Step 4: Simplify right side
    208.89x = 40,100.63
  5. Step 5: Solve for x
    x = 40,100.63/208.89
  6. Step 6: Final answer
    x = 191.97

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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.