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Finding the Fourth Proportional to 428.87, 642.62 and 412.86

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Solution

The fourth proportional to 428.87, 642.62 and 412.86 is: 618.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.87 : 642.62 = 412.86 : x
  2. Step 2: Convert to fraction form
    428.87/642.62 = 412.86/x
  3. Step 3: Cross multiply
    428.87x = 642.62 × 412.86
  4. Step 4: Simplify right side
    428.87x = 265,310.03
  5. Step 5: Solve for x
    x = 265,310.03/428.87
  6. Step 6: Final answer
    x = 618.63

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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.