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Finding the Fourth Proportional to 639.49, 959.24 and 206.65

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Solution

The fourth proportional to 639.49, 959.24 and 206.65 is: 309.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.49 : 959.24 = 206.65 : x
  2. Step 2: Convert to fraction form
    639.49/959.24 = 206.65/x
  3. Step 3: Cross multiply
    639.49x = 959.24 × 206.65
  4. Step 4: Simplify right side
    639.49x = 198,226.95
  5. Step 5: Solve for x
    x = 198,226.95/639.49
  6. Step 6: Final answer
    x = 309.98

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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.