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Finding the Fourth Proportional to 639.91, 959.66 and 274.60

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Solution

The fourth proportional to 639.91, 959.66 and 274.60 is: 411.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.91 : 959.66 = 274.60 : x
  2. Step 2: Convert to fraction form
    639.91/959.66 = 274.60/x
  3. Step 3: Cross multiply
    639.91x = 959.66 × 274.60
  4. Step 4: Simplify right side
    639.91x = 263,522.64
  5. Step 5: Solve for x
    x = 263,522.64/639.91
  6. Step 6: Final answer
    x = 411.81

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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.