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Finding the Fourth Proportional to 639, 958.50 and 206.15

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Solution

The fourth proportional to 639, 958.50 and 206.15 is: 309.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    639 : 958.50 = 206.15 : x
  2. Step 2: Convert to fraction form
    639/958.50 = 206.15/x
  3. Step 3: Cross multiply
    639x = 958.50 × 206.15
  4. Step 4: Simplify right side
    639x = 197,589.98
  5. Step 5: Solve for x
    x = 197,589.98/639
  6. Step 6: Final answer
    x = 309.22

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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.