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Finding the Fourth Proportional to 80.74, 121.23 and 56.31

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Solution

The fourth proportional to 80.74, 121.23 and 56.31 is: 84.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.74 : 121.23 = 56.31 : x
  2. Step 2: Convert to fraction form
    80.74/121.23 = 56.31/x
  3. Step 3: Cross multiply
    80.74x = 121.23 × 56.31
  4. Step 4: Simplify right side
    80.74x = 6,826.46
  5. Step 5: Solve for x
    x = 6,826.46/80.74
  6. Step 6: Final answer
    x = 84.55

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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.