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Finding the Fourth Proportional to 639.39, 958.88 and 206.45

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Solution

The fourth proportional to 639.39, 958.88 and 206.45 is: 309.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.39 : 958.88 = 206.45 : x
  2. Step 2: Convert to fraction form
    639.39/958.88 = 206.45/x
  3. Step 3: Cross multiply
    639.39x = 958.88 × 206.45
  4. Step 4: Simplify right side
    639.39x = 197,954.95
  5. Step 5: Solve for x
    x = 197,954.95/639.39
  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.