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Finding the Fourth Proportional to 84.30, 126.42 and 80.94

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Solution

The fourth proportional to 84.30, 126.42 and 80.94 is: 121.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.30 : 126.42 = 80.94 : x
  2. Step 2: Convert to fraction form
    84.30/126.42 = 80.94/x
  3. Step 3: Cross multiply
    84.30x = 126.42 × 80.94
  4. Step 4: Simplify right side
    84.30x = 10,232.43
  5. Step 5: Solve for x
    x = 10,232.43/84.30
  6. Step 6: Final answer
    x = 121.38

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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.