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Finding the Fourth Proportional to 139.19, 208.45 and 108.21

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Solution

The fourth proportional to 139.19, 208.45 and 108.21 is: 162.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.19 : 208.45 = 108.21 : x
  2. Step 2: Convert to fraction form
    139.19/208.45 = 108.21/x
  3. Step 3: Cross multiply
    139.19x = 208.45 × 108.21
  4. Step 4: Simplify right side
    139.19x = 22,556.40
  5. Step 5: Solve for x
    x = 22,556.40/139.19
  6. Step 6: Final answer
    x = 162.05

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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.