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Finding the Fourth Proportional to 139.80, 209.99 and 135.20

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Solution

The fourth proportional to 139.80, 209.99 and 135.20 is: 203.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.80 : 209.99 = 135.20 : x
  2. Step 2: Convert to fraction form
    139.80/209.99 = 135.20/x
  3. Step 3: Cross multiply
    139.80x = 209.99 × 135.20
  4. Step 4: Simplify right side
    139.80x = 28,388.92
  5. Step 5: Solve for x
    x = 28,388.92/139.80
  6. Step 6: Final answer
    x = 203.07

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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.