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Finding the Fourth Proportional to 84.22, 127.08 and 81.43

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Solution

The fourth proportional to 84.22, 127.08 and 81.43 is: 122.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.22 : 127.08 = 81.43 : x
  2. Step 2: Convert to fraction form
    84.22/127.08 = 81.43/x
  3. Step 3: Cross multiply
    84.22x = 127.08 × 81.43
  4. Step 4: Simplify right side
    84.22x = 10,347.81
  5. Step 5: Solve for x
    x = 10,347.81/84.22
  6. Step 6: Final answer
    x = 122.87

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.