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Finding the Fourth Proportional to 639.25, 959.51 and 379.71

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Solution

The fourth proportional to 639.25, 959.51 and 379.71 is: 569.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.25 : 959.51 = 379.71 : x
  2. Step 2: Convert to fraction form
    639.25/959.51 = 379.71/x
  3. Step 3: Cross multiply
    639.25x = 959.51 × 379.71
  4. Step 4: Simplify right side
    639.25x = 364,336.49
  5. Step 5: Solve for x
    x = 364,336.49/639.25
  6. Step 6: Final answer
    x = 569.95

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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.