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Finding the Fourth Proportional to 639.92, 882.28 and 485.04

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Solution

The fourth proportional to 639.92, 882.28 and 485.04 is: 668.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.92 : 882.28 = 485.04 : x
  2. Step 2: Convert to fraction form
    639.92/882.28 = 485.04/x
  3. Step 3: Cross multiply
    639.92x = 882.28 × 485.04
  4. Step 4: Simplify right side
    639.92x = 427,941.09
  5. Step 5: Solve for x
    x = 427,941.09/639.92
  6. Step 6: Final answer
    x = 668.74

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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.