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Finding the Fourth Proportional to 81.03, 121.20 and 61.56

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Solution

The fourth proportional to 81.03, 121.20 and 61.56 is: 92.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.03 : 121.20 = 61.56 : x
  2. Step 2: Convert to fraction form
    81.03/121.20 = 61.56/x
  3. Step 3: Cross multiply
    81.03x = 121.20 × 61.56
  4. Step 4: Simplify right side
    81.03x = 7,461.07
  5. Step 5: Solve for x
    x = 7,461.07/81.03
  6. Step 6: Final answer
    x = 92.08

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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.