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Finding the Fourth Proportional to 80.99, 121.46 and 55.31

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Solution

The fourth proportional to 80.99, 121.46 and 55.31 is: 82.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.99 : 121.46 = 55.31 : x
  2. Step 2: Convert to fraction form
    80.99/121.46 = 55.31/x
  3. Step 3: Cross multiply
    80.99x = 121.46 × 55.31
  4. Step 4: Simplify right side
    80.99x = 6,717.07
  5. Step 5: Solve for x
    x = 6,717.07/80.99
  6. Step 6: Final answer
    x = 82.94

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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.