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Finding the Fourth Proportional to 428.22, 642.32 and 330.86

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Solution

The fourth proportional to 428.22, 642.32 and 330.86 is: 496.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.22 : 642.32 = 330.86 : x
  2. Step 2: Convert to fraction form
    428.22/642.32 = 330.86/x
  3. Step 3: Cross multiply
    428.22x = 642.32 × 330.86
  4. Step 4: Simplify right side
    428.22x = 212,518.00
  5. Step 5: Solve for x
    x = 212,518.00/428.22
  6. Step 6: Final answer
    x = 496.28

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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.