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Finding the Fourth Proportional to 438.21, 656.64 and 255.56

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Solution

The fourth proportional to 438.21, 656.64 and 255.56 is: 382.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    438.21 : 656.64 = 255.56 : x
  2. Step 2: Convert to fraction form
    438.21/656.64 = 255.56/x
  3. Step 3: Cross multiply
    438.21x = 656.64 × 255.56
  4. Step 4: Simplify right side
    438.21x = 167,807.64
  5. Step 5: Solve for x
    x = 167,807.64/438.21
  6. Step 6: Final answer
    x = 382.94

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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.