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Finding the Fourth Proportional to 640.81, 961.31 and 275.68

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Solution

The fourth proportional to 640.81, 961.31 and 275.68 is: 413.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.81 : 961.31 = 275.68 : x
  2. Step 2: Convert to fraction form
    640.81/961.31 = 275.68/x
  3. Step 3: Cross multiply
    640.81x = 961.31 × 275.68
  4. Step 4: Simplify right side
    640.81x = 265,013.94
  5. Step 5: Solve for x
    x = 265,013.94/640.81
  6. Step 6: Final answer
    x = 413.56

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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.