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Finding the Fourth Proportional to 80.80, 121.63 and 61.64

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Solution

The fourth proportional to 80.80, 121.63 and 61.64 is: 92.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.80 : 121.63 = 61.64 : x
  2. Step 2: Convert to fraction form
    80.80/121.63 = 61.64/x
  3. Step 3: Cross multiply
    80.80x = 121.63 × 61.64
  4. Step 4: Simplify right side
    80.80x = 7,496.57
  5. Step 5: Solve for x
    x = 7,496.57/80.80
  6. Step 6: Final answer
    x = 92.78

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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.