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Finding the Fourth Proportional to 413.20, 619.80 and 407.80

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Solution

The fourth proportional to 413.20, 619.80 and 407.80 is: 611.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    413.20 : 619.80 = 407.80 : x
  2. Step 2: Convert to fraction form
    413.20/619.80 = 407.80/x
  3. Step 3: Cross multiply
    413.20x = 619.80 × 407.80
  4. Step 4: Simplify right side
    413.20x = 252,754.44
  5. Step 5: Solve for x
    x = 252,754.44/413.20
  6. Step 6: Final answer
    x = 611.70

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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.