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Finding the Fourth Proportional to 83.70, 125.40 and 54.87

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Solution

The fourth proportional to 83.70, 125.40 and 54.87 is: 82.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    83.70 : 125.40 = 54.87 : x
  2. Step 2: Convert to fraction form
    83.70/125.40 = 54.87/x
  3. Step 3: Cross multiply
    83.70x = 125.40 × 54.87
  4. Step 4: Simplify right side
    83.70x = 6,881.37
  5. Step 5: Solve for x
    x = 6,881.37/83.70
  6. Step 6: Final answer
    x = 82.21

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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.