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Finding the Fourth Proportional to 83.50, 124.40 and 81.11

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Solution

The fourth proportional to 83.50, 124.40 and 81.11 is: 120.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    83.50 : 124.40 = 81.11 : x
  2. Step 2: Convert to fraction form
    83.50/124.40 = 81.11/x
  3. Step 3: Cross multiply
    83.50x = 124.40 × 81.11
  4. Step 4: Simplify right side
    83.50x = 10,090.60
  5. Step 5: Solve for x
    x = 10,090.60/83.50
  6. Step 6: Final answer
    x = 120.85

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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.