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Finding the Fourth Proportional to 80.80, 121.09 and 48.31

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Solution

The fourth proportional to 80.80, 121.09 and 48.31 is: 72.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.80 : 121.09 = 48.31 : x
  2. Step 2: Convert to fraction form
    80.80/121.09 = 48.31/x
  3. Step 3: Cross multiply
    80.80x = 121.09 × 48.31
  4. Step 4: Simplify right side
    80.80x = 5,849.43
  5. Step 5: Solve for x
    x = 5,849.43/80.80
  6. Step 6: Final answer
    x = 72.40

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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.