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Finding the Fourth Proportional to 428.60, 642.63 and 222.86

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Solution

The fourth proportional to 428.60, 642.63 and 222.86 is: 334.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.60 : 642.63 = 222.86 : x
  2. Step 2: Convert to fraction form
    428.60/642.63 = 222.86/x
  3. Step 3: Cross multiply
    428.60x = 642.63 × 222.86
  4. Step 4: Simplify right side
    428.60x = 143,216.52
  5. Step 5: Solve for x
    x = 143,216.52/428.60
  6. Step 6: Final answer
    x = 334.15

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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.