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Finding the Fourth Proportional to 413.28, 619.86 and 120.78

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Solution

The fourth proportional to 413.28, 619.86 and 120.78 is: 181.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    413.28 : 619.86 = 120.78 : x
  2. Step 2: Convert to fraction form
    413.28/619.86 = 120.78/x
  3. Step 3: Cross multiply
    413.28x = 619.86 × 120.78
  4. Step 4: Simplify right side
    413.28x = 74,866.69
  5. Step 5: Solve for x
    x = 74,866.69/413.28
  6. Step 6: Final answer
    x = 181.15

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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.