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Finding the Fourth Proportional to 81.23, 121.79 and 35.55

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Solution

The fourth proportional to 81.23, 121.79 and 35.55 is: 53.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.23 : 121.79 = 35.55 : x
  2. Step 2: Convert to fraction form
    81.23/121.79 = 35.55/x
  3. Step 3: Cross multiply
    81.23x = 121.79 × 35.55
  4. Step 4: Simplify right side
    81.23x = 4,329.72
  5. Step 5: Solve for x
    x = 4,329.72/81.23
  6. Step 6: Final answer
    x = 53.31

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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.