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Finding the Fourth Proportional to 428.92, 642.78 and 223.08

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Solution

The fourth proportional to 428.92, 642.78 and 223.08 is: 334.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.92 : 642.78 = 223.08 : x
  2. Step 2: Convert to fraction form
    428.92/642.78 = 223.08/x
  3. Step 3: Cross multiply
    428.92x = 642.78 × 223.08
  4. Step 4: Simplify right side
    428.92x = 143,391.36
  5. Step 5: Solve for x
    x = 143,391.36/428.92
  6. Step 6: Final answer
    x = 334.31

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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.