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Finding the Fourth Proportional to 139.52, 209.30 and 102.88

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Solution

The fourth proportional to 139.52, 209.30 and 102.88 is: 154.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.52 : 209.30 = 102.88 : x
  2. Step 2: Convert to fraction form
    139.52/209.30 = 102.88/x
  3. Step 3: Cross multiply
    139.52x = 209.30 × 102.88
  4. Step 4: Simplify right side
    139.52x = 21,532.78
  5. Step 5: Solve for x
    x = 21,532.78/139.52
  6. Step 6: Final answer
    x = 154.33

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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.