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Finding the Fourth Proportional to 120.26, 180.45 and 84.21

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Solution

The fourth proportional to 120.26, 180.45 and 84.21 is: 126.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.26 : 180.45 = 84.21 : x
  2. Step 2: Convert to fraction form
    120.26/180.45 = 84.21/x
  3. Step 3: Cross multiply
    120.26x = 180.45 × 84.21
  4. Step 4: Simplify right side
    120.26x = 15,195.69
  5. Step 5: Solve for x
    x = 15,195.69/120.26
  6. Step 6: Final answer
    x = 126.36

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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.