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Finding the Fourth Proportional to 256.53, 385.41 and 221.31

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Solution

The fourth proportional to 256.53, 385.41 and 221.31 is: 332.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.53 : 385.41 = 221.31 : x
  2. Step 2: Convert to fraction form
    256.53/385.41 = 221.31/x
  3. Step 3: Cross multiply
    256.53x = 385.41 × 221.31
  4. Step 4: Simplify right side
    256.53x = 85,295.09
  5. Step 5: Solve for x
    x = 85,295.09/256.53
  6. Step 6: Final answer
    x = 332.50

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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.