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Finding the Fourth Proportional to 85.41, 127.31 and 82.40

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Solution

The fourth proportional to 85.41, 127.31 and 82.40 is: 122.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.41 : 127.31 = 82.40 : x
  2. Step 2: Convert to fraction form
    85.41/127.31 = 82.40/x
  3. Step 3: Cross multiply
    85.41x = 127.31 × 82.40
  4. Step 4: Simplify right side
    85.41x = 10,489.30
  5. Step 5: Solve for x
    x = 10,489.30/85.41
  6. Step 6: Final answer
    x = 122.81

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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.