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Finding the Fourth Proportional to 84.12, 125.57 and 83.21

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Solution

The fourth proportional to 84.12, 125.57 and 83.21 is: 124.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.12 : 125.57 = 83.21 : x
  2. Step 2: Convert to fraction form
    84.12/125.57 = 83.21/x
  3. Step 3: Cross multiply
    84.12x = 125.57 × 83.21
  4. Step 4: Simplify right side
    84.12x = 10,447.64
  5. Step 5: Solve for x
    x = 10,447.64/84.12
  6. Step 6: Final answer
    x = 124.20

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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.