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Finding the Fourth Proportional to 85.25, 127.78 and 71.89

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Solution

The fourth proportional to 85.25, 127.78 and 71.89 is: 107.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.25 : 127.78 = 71.89 : x
  2. Step 2: Convert to fraction form
    85.25/127.78 = 71.89/x
  3. Step 3: Cross multiply
    85.25x = 127.78 × 71.89
  4. Step 4: Simplify right side
    85.25x = 9,185.61
  5. Step 5: Solve for x
    x = 9,185.61/85.25
  6. Step 6: Final answer
    x = 107.75

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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.