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Finding the Fourth Proportional to 139.80, 209.64 and 102.66

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Solution

The fourth proportional to 139.80, 209.64 and 102.66 is: 153.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.80 : 209.64 = 102.66 : x
  2. Step 2: Convert to fraction form
    139.80/209.64 = 102.66/x
  3. Step 3: Cross multiply
    139.80x = 209.64 × 102.66
  4. Step 4: Simplify right side
    139.80x = 21,521.64
  5. Step 5: Solve for x
    x = 21,521.64/139.80
  6. Step 6: Final answer
    x = 153.95

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These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.