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Finding the Fourth Proportional to 85.27, 127.71 and 78.61

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Solution

The fourth proportional to 85.27, 127.71 and 78.61 is: 117.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.27 : 127.71 = 78.61 : x
  2. Step 2: Convert to fraction form
    85.27/127.71 = 78.61/x
  3. Step 3: Cross multiply
    85.27x = 127.71 × 78.61
  4. Step 4: Simplify right side
    85.27x = 10,039.28
  5. Step 5: Solve for x
    x = 10,039.28/85.27
  6. Step 6: Final answer
    x = 117.74

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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.