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Finding the Fourth Proportional to 639.73, 959.80 and 485.83

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Solution

The fourth proportional to 639.73, 959.80 and 485.83 is: 728.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.73 : 959.80 = 485.83 : x
  2. Step 2: Convert to fraction form
    639.73/959.80 = 485.83/x
  3. Step 3: Cross multiply
    639.73x = 959.80 × 485.83
  4. Step 4: Simplify right side
    639.73x = 466,299.63
  5. Step 5: Solve for x
    x = 466,299.63/639.73
  6. Step 6: Final answer
    x = 728.90

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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.