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Finding the Fourth Proportional to 133.09, 199.40 and 81.55

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Solution

The fourth proportional to 133.09, 199.40 and 81.55 is: 122.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    133.09 : 199.40 = 81.55 : x
  2. Step 2: Convert to fraction form
    133.09/199.40 = 81.55/x
  3. Step 3: Cross multiply
    133.09x = 199.40 × 81.55
  4. Step 4: Simplify right side
    133.09x = 16,261.07
  5. Step 5: Solve for x
    x = 16,261.07/133.09
  6. Step 6: Final answer
    x = 122.18

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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.