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Finding the Fourth Proportional to 640.49, 961.13 and 275.78

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Solution

The fourth proportional to 640.49, 961.13 and 275.78 is: 413.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.49 : 961.13 = 275.78 : x
  2. Step 2: Convert to fraction form
    640.49/961.13 = 275.78/x
  3. Step 3: Cross multiply
    640.49x = 961.13 × 275.78
  4. Step 4: Simplify right side
    640.49x = 265,063.52
  5. Step 5: Solve for x
    x = 265,063.52/640.49
  6. Step 6: Final answer
    x = 413.85

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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.