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Finding the Fourth Proportional to 329.21, 493.78 and 85.73

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Solution

The fourth proportional to 329.21, 493.78 and 85.73 is: 128.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    329.21 : 493.78 = 85.73 : x
  2. Step 2: Convert to fraction form
    329.21/493.78 = 85.73/x
  3. Step 3: Cross multiply
    329.21x = 493.78 × 85.73
  4. Step 4: Simplify right side
    329.21x = 42,331.33
  5. Step 5: Solve for x
    x = 42,331.33/329.21
  6. Step 6: Final answer
    x = 128.58

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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.