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Finding the Fourth Proportional to 85.89, 128.82 and 28.89

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Solution

The fourth proportional to 85.89, 128.82 and 28.89 is: 43.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.89 : 128.82 = 28.89 : x
  2. Step 2: Convert to fraction form
    85.89/128.82 = 28.89/x
  3. Step 3: Cross multiply
    85.89x = 128.82 × 28.89
  4. Step 4: Simplify right side
    85.89x = 3,721.61
  5. Step 5: Solve for x
    x = 3,721.61/85.89
  6. Step 6: Final answer
    x = 43.33

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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.