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Finding the Fourth Proportional to 80.75, 121.13 and 70.72

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Solution

The fourth proportional to 80.75, 121.13 and 70.72 is: 106.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.75 : 121.13 = 70.72 : x
  2. Step 2: Convert to fraction form
    80.75/121.13 = 70.72/x
  3. Step 3: Cross multiply
    80.75x = 121.13 × 70.72
  4. Step 4: Simplify right side
    80.75x = 8,566.60
  5. Step 5: Solve for x
    x = 8,566.60/80.75
  6. Step 6: Final answer
    x = 106.09

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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.