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Finding the Fourth Proportional to 1,279.36, 1,919.36 and 413.76

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Solution

The fourth proportional to 1,279.36, 1,919.36 and 413.76 is: 620.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,279.36 : 1,919.36 = 413.76 : x
  2. Step 2: Convert to fraction form
    1,279.36/1,919.36 = 413.76/x
  3. Step 3: Cross multiply
    1,279.36x = 1,919.36 × 413.76
  4. Step 4: Simplify right side
    1,279.36x = 794,154.39
  5. Step 5: Solve for x
    x = 794,154.39/1,279.36
  6. Step 6: Final answer
    x = 620.74

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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.