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Finding the Fourth Proportional to 639.22, 958.88 and 206.39

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Solution

The fourth proportional to 639.22, 958.88 and 206.39 is: 309.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.22 : 958.88 = 206.39 : x
  2. Step 2: Convert to fraction form
    639.22/958.88 = 206.39/x
  3. Step 3: Cross multiply
    639.22x = 958.88 × 206.39
  4. Step 4: Simplify right side
    639.22x = 197,903.24
  5. Step 5: Solve for x
    x = 197,903.24/639.22
  6. Step 6: Final answer
    x = 309.60

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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.