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Finding the Fourth Proportional to 80.80, 120.77 and 56.80

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Solution

The fourth proportional to 80.80, 120.77 and 56.80 is: 84.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.80 : 120.77 = 56.80 : x
  2. Step 2: Convert to fraction form
    80.80/120.77 = 56.80/x
  3. Step 3: Cross multiply
    80.80x = 120.77 × 56.80
  4. Step 4: Simplify right side
    80.80x = 6,859.74
  5. Step 5: Solve for x
    x = 6,859.74/80.80
  6. Step 6: Final answer
    x = 84.90

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.