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Finding the Fourth Proportional to 81.95, 123.03 and 66.69

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Solution

The fourth proportional to 81.95, 123.03 and 66.69 is: 100.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.95 : 123.03 = 66.69 : x
  2. Step 2: Convert to fraction form
    81.95/123.03 = 66.69/x
  3. Step 3: Cross multiply
    81.95x = 123.03 × 66.69
  4. Step 4: Simplify right side
    81.95x = 8,204.87
  5. Step 5: Solve for x
    x = 8,204.87/81.95
  6. Step 6: Final answer
    x = 100.13

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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.