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Finding the Fourth Proportional to 133.80, 200.86 and 85.80

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Solution

The fourth proportional to 133.80, 200.86 and 85.80 is: 128.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    133.80 : 200.86 = 85.80 : x
  2. Step 2: Convert to fraction form
    133.80/200.86 = 85.80/x
  3. Step 3: Cross multiply
    133.80x = 200.86 × 85.80
  4. Step 4: Simplify right side
    133.80x = 17,233.79
  5. Step 5: Solve for x
    x = 17,233.79/133.80
  6. Step 6: Final answer
    x = 128.80

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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.