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Finding the Fourth Proportional to 428.45, 642.08 and 222.59

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Solution

The fourth proportional to 428.45, 642.08 and 222.59 is: 333.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.45 : 642.08 = 222.59 : x
  2. Step 2: Convert to fraction form
    428.45/642.08 = 222.59/x
  3. Step 3: Cross multiply
    428.45x = 642.08 × 222.59
  4. Step 4: Simplify right side
    428.45x = 142,920.59
  5. Step 5: Solve for x
    x = 142,920.59/428.45
  6. Step 6: Final answer
    x = 333.58

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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.