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Finding the Fourth Proportional to 139.84, 208.76 and 121.62

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Solution

The fourth proportional to 139.84, 208.76 and 121.62 is: 181.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.84 : 208.76 = 121.62 : x
  2. Step 2: Convert to fraction form
    139.84/208.76 = 121.62/x
  3. Step 3: Cross multiply
    139.84x = 208.76 × 121.62
  4. Step 4: Simplify right side
    139.84x = 25,389.09
  5. Step 5: Solve for x
    x = 25,389.09/139.84
  6. Step 6: Final answer
    x = 181.56

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.