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Finding the Fourth Proportional to 139.68, 209.40 and 88.20

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Solution

The fourth proportional to 139.68, 209.40 and 88.20 is: 132.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.68 : 209.40 = 88.20 : x
  2. Step 2: Convert to fraction form
    139.68/209.40 = 88.20/x
  3. Step 3: Cross multiply
    139.68x = 209.40 × 88.20
  4. Step 4: Simplify right side
    139.68x = 18,468.03
  5. Step 5: Solve for x
    x = 18,468.03/139.68
  6. Step 6: Final answer
    x = 132.22

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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.