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Finding the Fourth Proportional to 85.97, 128.90 and 60.35

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Solution

The fourth proportional to 85.97, 128.90 and 60.35 is: 90.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.97 : 128.90 = 60.35 : x
  2. Step 2: Convert to fraction form
    85.97/128.90 = 60.35/x
  3. Step 3: Cross multiply
    85.97x = 128.90 × 60.35
  4. Step 4: Simplify right side
    85.97x = 7,778.62
  5. Step 5: Solve for x
    x = 7,778.62/85.97
  6. Step 6: Final answer
    x = 90.48

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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.