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Finding the Fourth Proportional to 84.76, 126.90 and 54.36

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Solution

The fourth proportional to 84.76, 126.90 and 54.36 is: 81.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.76 : 126.90 = 54.36 : x
  2. Step 2: Convert to fraction form
    84.76/126.90 = 54.36/x
  3. Step 3: Cross multiply
    84.76x = 126.90 × 54.36
  4. Step 4: Simplify right side
    84.76x = 6,898.28
  5. Step 5: Solve for x
    x = 6,898.28/84.76
  6. Step 6: Final answer
    x = 81.39

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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.