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Finding the Fourth Proportional to 386.22, 578.69 and 221.48

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Solution

The fourth proportional to 386.22, 578.69 and 221.48 is: 331.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.22 : 578.69 = 221.48 : x
  2. Step 2: Convert to fraction form
    386.22/578.69 = 221.48/x
  3. Step 3: Cross multiply
    386.22x = 578.69 × 221.48
  4. Step 4: Simplify right side
    386.22x = 128,171.76
  5. Step 5: Solve for x
    x = 128,171.76/386.22
  6. Step 6: Final answer
    x = 331.86

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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.