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Finding the Fourth Proportional to 660.90, 990.39 and 413.98

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Solution

The fourth proportional to 660.90, 990.39 and 413.98 is: 620.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.90 : 990.39 = 413.98 : x
  2. Step 2: Convert to fraction form
    660.90/990.39 = 413.98/x
  3. Step 3: Cross multiply
    660.90x = 990.39 × 413.98
  4. Step 4: Simplify right side
    660.90x = 410,001.65
  5. Step 5: Solve for x
    x = 410,001.65/660.90
  6. Step 6: Final answer
    x = 620.37

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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.