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Finding the Fourth Proportional to 639.15, 956.85 and 485.68

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Solution

The fourth proportional to 639.15, 956.85 and 485.68 is: 727.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.15 : 956.85 = 485.68 : x
  2. Step 2: Convert to fraction form
    639.15/956.85 = 485.68/x
  3. Step 3: Cross multiply
    639.15x = 956.85 × 485.68
  4. Step 4: Simplify right side
    639.15x = 464,722.91
  5. Step 5: Solve for x
    x = 464,722.91/639.15
  6. Step 6: Final answer
    x = 727.10

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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.