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Finding the Fourth Proportional to 139.17, 208.66 and 105.15

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Solution

The fourth proportional to 139.17, 208.66 and 105.15 is: 157.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.17 : 208.66 = 105.15 : x
  2. Step 2: Convert to fraction form
    139.17/208.66 = 105.15/x
  3. Step 3: Cross multiply
    139.17x = 208.66 × 105.15
  4. Step 4: Simplify right side
    139.17x = 21,940.60
  5. Step 5: Solve for x
    x = 21,940.60/139.17
  6. Step 6: Final answer
    x = 157.65

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.