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Finding the Fourth Proportional to 56.20, 77.90 and 54.31

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Solution

The fourth proportional to 56.20, 77.90 and 54.31 is: 75.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    56.20 : 77.90 = 54.31 : x
  2. Step 2: Convert to fraction form
    56.20/77.90 = 54.31/x
  3. Step 3: Cross multiply
    56.20x = 77.90 × 54.31
  4. Step 4: Simplify right side
    56.20x = 4,230.69
  5. Step 5: Solve for x
    x = 4,230.69/56.20
  6. Step 6: Final answer
    x = 75.28

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.