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Finding the Fourth Proportional to 639.15, 956.66 and 330.57

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Solution

The fourth proportional to 639.15, 956.66 and 330.57 is: 494.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.15 : 956.66 = 330.57 : x
  2. Step 2: Convert to fraction form
    639.15/956.66 = 330.57/x
  3. Step 3: Cross multiply
    639.15x = 956.66 × 330.57
  4. Step 4: Simplify right side
    639.15x = 316,241.44
  5. Step 5: Solve for x
    x = 316,241.44/639.15
  6. Step 6: Final answer
    x = 494.78

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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.