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Finding the Fourth Proportional to 619.40, 929.55 and 413.90

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Solution

The fourth proportional to 619.40, 929.55 and 413.90 is: 621.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    619.40 : 929.55 = 413.90 : x
  2. Step 2: Convert to fraction form
    619.40/929.55 = 413.90/x
  3. Step 3: Cross multiply
    619.40x = 929.55 × 413.90
  4. Step 4: Simplify right side
    619.40x = 384,740.75
  5. Step 5: Solve for x
    x = 384,740.75/619.40
  6. Step 6: Final answer
    x = 621.15

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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.