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Finding the Fourth Proportional to 85.22, 127.78 and 72.46

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Solution

The fourth proportional to 85.22, 127.78 and 72.46 is: 108.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.22 : 127.78 = 72.46 : x
  2. Step 2: Convert to fraction form
    85.22/127.78 = 72.46/x
  3. Step 3: Cross multiply
    85.22x = 127.78 × 72.46
  4. Step 4: Simplify right side
    85.22x = 9,258.94
  5. Step 5: Solve for x
    x = 9,258.94/85.22
  6. Step 6: Final answer
    x = 108.65

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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.