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Finding the Fourth Proportional to 139.04, 208.60 and 138.80

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Solution

The fourth proportional to 139.04, 208.60 and 138.80 is: 208.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.04 : 208.60 = 138.80 : x
  2. Step 2: Convert to fraction form
    139.04/208.60 = 138.80/x
  3. Step 3: Cross multiply
    139.04x = 208.60 × 138.80
  4. Step 4: Simplify right side
    139.04x = 28,953.68
  5. Step 5: Solve for x
    x = 28,953.68/139.04
  6. Step 6: Final answer
    x = 208.24

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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.