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Finding the Fourth Proportional to 639.29, 958.76 and 206.21

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Solution

The fourth proportional to 639.29, 958.76 and 206.21 is: 309.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.29 : 958.76 = 206.21 : x
  2. Step 2: Convert to fraction form
    639.29/958.76 = 206.21/x
  3. Step 3: Cross multiply
    639.29x = 958.76 × 206.21
  4. Step 4: Simplify right side
    639.29x = 197,704.87
  5. Step 5: Solve for x
    x = 197,704.87/639.29
  6. Step 6: Final answer
    x = 309.26

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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.