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Finding the Fourth Proportional to 80.64, 121.39 and 69.48

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Solution

The fourth proportional to 80.64, 121.39 and 69.48 is: 104.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.64 : 121.39 = 69.48 : x
  2. Step 2: Convert to fraction form
    80.64/121.39 = 69.48/x
  3. Step 3: Cross multiply
    80.64x = 121.39 × 69.48
  4. Step 4: Simplify right side
    80.64x = 8,433.57
  5. Step 5: Solve for x
    x = 8,433.57/80.64
  6. Step 6: Final answer
    x = 104.58

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.