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Finding the Fourth Proportional to 639.33, 881.58 and 492.31

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Solution

The fourth proportional to 639.33, 881.58 and 492.31 is: 678.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.33 : 881.58 = 492.31 : x
  2. Step 2: Convert to fraction form
    639.33/881.58 = 492.31/x
  3. Step 3: Cross multiply
    639.33x = 881.58 × 492.31
  4. Step 4: Simplify right side
    639.33x = 434,010.65
  5. Step 5: Solve for x
    x = 434,010.65/639.33
  6. Step 6: Final answer
    x = 678.85

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.