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Finding the Fourth Proportional to 120.82, 180.81 and 98.90

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Solution

The fourth proportional to 120.82, 180.81 and 98.90 is: 148.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.82 : 180.81 = 98.90 : x
  2. Step 2: Convert to fraction form
    120.82/180.81 = 98.90/x
  3. Step 3: Cross multiply
    120.82x = 180.81 × 98.90
  4. Step 4: Simplify right side
    120.82x = 17,882.11
  5. Step 5: Solve for x
    x = 17,882.11/120.82
  6. Step 6: Final answer
    x = 148.01

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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.