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Finding the Fourth Proportional to 438.40, 656.38 and 221.52

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Solution

The fourth proportional to 438.40, 656.38 and 221.52 is: 331.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    438.40 : 656.38 = 221.52 : x
  2. Step 2: Convert to fraction form
    438.40/656.38 = 221.52/x
  3. Step 3: Cross multiply
    438.40x = 656.38 × 221.52
  4. Step 4: Simplify right side
    438.40x = 145,401.30
  5. Step 5: Solve for x
    x = 145,401.30/438.40
  6. Step 6: Final answer
    x = 331.66

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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.