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Finding the Fourth Proportional to 81.40, 112.26 and 72.67

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Solution

The fourth proportional to 81.40, 112.26 and 72.67 is: 100.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.40 : 112.26 = 72.67 : x
  2. Step 2: Convert to fraction form
    81.40/112.26 = 72.67/x
  3. Step 3: Cross multiply
    81.40x = 112.26 × 72.67
  4. Step 4: Simplify right side
    81.40x = 8,157.93
  5. Step 5: Solve for x
    x = 8,157.93/81.40
  6. Step 6: Final answer
    x = 100.22

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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.