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Finding the Fourth Proportional to 639.65, 959.67 and 274.47

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Solution

The fourth proportional to 639.65, 959.67 and 274.47 is: 411.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.65 : 959.67 = 274.47 : x
  2. Step 2: Convert to fraction form
    639.65/959.67 = 274.47/x
  3. Step 3: Cross multiply
    639.65x = 959.67 × 274.47
  4. Step 4: Simplify right side
    639.65x = 263,400.62
  5. Step 5: Solve for x
    x = 263,400.62/639.65
  6. Step 6: Final answer
    x = 411.79

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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.