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Finding the Fourth Proportional to 665.39, 917.91 and 413.21

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Solution

The fourth proportional to 665.39, 917.91 and 413.21 is: 570.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.39 : 917.91 = 413.21 : x
  2. Step 2: Convert to fraction form
    665.39/917.91 = 413.21/x
  3. Step 3: Cross multiply
    665.39x = 917.91 × 413.21
  4. Step 4: Simplify right side
    665.39x = 379,285.00
  5. Step 5: Solve for x
    x = 379,285.00/665.39
  6. Step 6: Final answer
    x = 570.02

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.