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Finding the Fourth Proportional to 80.21, 121.05 and 77.50

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Solution

The fourth proportional to 80.21, 121.05 and 77.50 is: 116.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.21 : 121.05 = 77.50 : x
  2. Step 2: Convert to fraction form
    80.21/121.05 = 77.50/x
  3. Step 3: Cross multiply
    80.21x = 121.05 × 77.50
  4. Step 4: Simplify right side
    80.21x = 9,380.38
  5. Step 5: Solve for x
    x = 9,380.38/80.21
  6. Step 6: Final answer
    x = 116.95

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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.