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Finding the Fourth Proportional to 428.19, 642.16 and 222.65

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Solution

The fourth proportional to 428.19, 642.16 and 222.65 is: 333.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.19 : 642.16 = 222.65 : x
  2. Step 2: Convert to fraction form
    428.19/642.16 = 222.65/x
  3. Step 3: Cross multiply
    428.19x = 642.16 × 222.65
  4. Step 4: Simplify right side
    428.19x = 142,976.40
  5. Step 5: Solve for x
    x = 142,976.40/428.19
  6. Step 6: Final answer
    x = 333.91

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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.