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Finding the Fourth Proportional to 428.21, 641.74 and 222.34

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Solution

The fourth proportional to 428.21, 641.74 and 222.34 is: 333.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.21 : 641.74 = 222.34 : x
  2. Step 2: Convert to fraction form
    428.21/641.74 = 222.34/x
  3. Step 3: Cross multiply
    428.21x = 641.74 × 222.34
  4. Step 4: Simplify right side
    428.21x = 142,684.47
  5. Step 5: Solve for x
    x = 142,684.47/428.21
  6. Step 6: Final answer
    x = 333.21

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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.