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Finding the Fourth Proportional to 428.42, 642.64 and 222.86

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Solution

The fourth proportional to 428.42, 642.64 and 222.86 is: 334.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.42 : 642.64 = 222.86 : x
  2. Step 2: Convert to fraction form
    428.42/642.64 = 222.86/x
  3. Step 3: Cross multiply
    428.42x = 642.64 × 222.86
  4. Step 4: Simplify right side
    428.42x = 143,215.54
  5. Step 5: Solve for x
    x = 143,215.54/428.42
  6. Step 6: Final answer
    x = 334.29

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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.