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Finding the Fourth Proportional to 85.31, 127.39 and 68

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Solution

The fourth proportional to 85.31, 127.39 and 68 is: 101.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.31 : 127.39 = 68 : x
  2. Step 2: Convert to fraction form
    85.31/127.39 = 68/x
  3. Step 3: Cross multiply
    85.31x = 127.39 × 68
  4. Step 4: Simplify right side
    85.31x = 8,662.52
  5. Step 5: Solve for x
    x = 8,662.52/85.31
  6. Step 6: Final answer
    x = 101.54

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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.