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Finding the Fourth Proportional to 139.86, 208.44 and 138.51

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Solution

The fourth proportional to 139.86, 208.44 and 138.51 is: 206.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.86 : 208.44 = 138.51 : x
  2. Step 2: Convert to fraction form
    139.86/208.44 = 138.51/x
  3. Step 3: Cross multiply
    139.86x = 208.44 × 138.51
  4. Step 4: Simplify right side
    139.86x = 28,871.02
  5. Step 5: Solve for x
    x = 28,871.02/139.86
  6. Step 6: Final answer
    x = 206.43

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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.