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Finding the Fourth Proportional to 56.40, 83.97 and 54.78

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Solution

The fourth proportional to 56.40, 83.97 and 54.78 is: 81.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    56.40 : 83.97 = 54.78 : x
  2. Step 2: Convert to fraction form
    56.40/83.97 = 54.78/x
  3. Step 3: Cross multiply
    56.40x = 83.97 × 54.78
  4. Step 4: Simplify right side
    56.40x = 4,599.88
  5. Step 5: Solve for x
    x = 4,599.88/56.40
  6. Step 6: Final answer
    x = 81.56

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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.