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Finding the Fourth Proportional to 258.89, 388.17 and 220.64

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Solution

The fourth proportional to 258.89, 388.17 and 220.64 is: 330.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.89 : 388.17 = 220.64 : x
  2. Step 2: Convert to fraction form
    258.89/388.17 = 220.64/x
  3. Step 3: Cross multiply
    258.89x = 388.17 × 220.64
  4. Step 4: Simplify right side
    258.89x = 85,645.83
  5. Step 5: Solve for x
    x = 85,645.83/258.89
  6. Step 6: Final answer
    x = 330.82

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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.