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Finding the Fourth Proportional to 89.51, 122.82 and 81.30

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Solution

The fourth proportional to 89.51, 122.82 and 81.30 is: 111.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    89.51 : 122.82 = 81.30 : x
  2. Step 2: Convert to fraction form
    89.51/122.82 = 81.30/x
  3. Step 3: Cross multiply
    89.51x = 122.82 × 81.30
  4. Step 4: Simplify right side
    89.51x = 9,985.27
  5. Step 5: Solve for x
    x = 9,985.27/89.51
  6. Step 6: Final answer
    x = 111.56

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.