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Finding the Fourth Proportional to 81.95, 123.44 and 80.89

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Solution

The fourth proportional to 81.95, 123.44 and 80.89 is: 121.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.95 : 123.44 = 80.89 : x
  2. Step 2: Convert to fraction form
    81.95/123.44 = 80.89/x
  3. Step 3: Cross multiply
    81.95x = 123.44 × 80.89
  4. Step 4: Simplify right side
    81.95x = 9,985.06
  5. Step 5: Solve for x
    x = 9,985.06/81.95
  6. Step 6: Final answer
    x = 121.84

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.