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Finding the Fourth Proportional to 85.50, 118.26 and 81.72

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Solution

The fourth proportional to 85.50, 118.26 and 81.72 is: 113.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.50 : 118.26 = 81.72 : x
  2. Step 2: Convert to fraction form
    85.50/118.26 = 81.72/x
  3. Step 3: Cross multiply
    85.50x = 118.26 × 81.72
  4. Step 4: Simplify right side
    85.50x = 9,664.21
  5. Step 5: Solve for x
    x = 9,664.21/85.50
  6. Step 6: Final answer
    x = 113.03

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.