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Finding the Fourth Proportional to 139.02, 208.35 and 102.90

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Solution

The fourth proportional to 139.02, 208.35 and 102.90 is: 154.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.02 : 208.35 = 102.90 : x
  2. Step 2: Convert to fraction form
    139.02/208.35 = 102.90/x
  3. Step 3: Cross multiply
    139.02x = 208.35 × 102.90
  4. Step 4: Simplify right side
    139.02x = 21,439.22
  5. Step 5: Solve for x
    x = 21,439.22/139.02
  6. Step 6: Final answer
    x = 154.22

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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.