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Finding the Fourth Proportional to 639.73, 958.61 and 379.21

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Solution

The fourth proportional to 639.73, 958.61 and 379.21 is: 568.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.73 : 958.61 = 379.21 : x
  2. Step 2: Convert to fraction form
    639.73/958.61 = 379.21/x
  3. Step 3: Cross multiply
    639.73x = 958.61 × 379.21
  4. Step 4: Simplify right side
    639.73x = 363,507.81
  5. Step 5: Solve for x
    x = 363,507.81/639.73
  6. Step 6: Final answer
    x = 568.23

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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.