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Finding the Fourth Proportional to 80.55, 120.78 and 56.22

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Solution

The fourth proportional to 80.55, 120.78 and 56.22 is: 84.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.55 : 120.78 = 56.22 : x
  2. Step 2: Convert to fraction form
    80.55/120.78 = 56.22/x
  3. Step 3: Cross multiply
    80.55x = 120.78 × 56.22
  4. Step 4: Simplify right side
    80.55x = 6,790.25
  5. Step 5: Solve for x
    x = 6,790.25/80.55
  6. Step 6: Final answer
    x = 84.30

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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.