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Finding the Fourth Proportional to 84.42, 126.60 and 81.18

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Solution

The fourth proportional to 84.42, 126.60 and 81.18 is: 121.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.42 : 126.60 = 81.18 : x
  2. Step 2: Convert to fraction form
    84.42/126.60 = 81.18/x
  3. Step 3: Cross multiply
    84.42x = 126.60 × 81.18
  4. Step 4: Simplify right side
    84.42x = 10,277.39
  5. Step 5: Solve for x
    x = 10,277.39/84.42
  6. Step 6: Final answer
    x = 121.74

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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.