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Finding the Fourth Proportional to 639.72, 883.12 and 492.68

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Solution

The fourth proportional to 639.72, 883.12 and 492.68 is: 680.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.72 : 883.12 = 492.68 : x
  2. Step 2: Convert to fraction form
    639.72/883.12 = 492.68/x
  3. Step 3: Cross multiply
    639.72x = 883.12 × 492.68
  4. Step 4: Simplify right side
    639.72x = 435,095.56
  5. Step 5: Solve for x
    x = 435,095.56/639.72
  6. Step 6: Final answer
    x = 680.13

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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.