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Finding the Fourth Proportional to 809.20, 1,210.20 and 679.60

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Solution

The fourth proportional to 809.20, 1,210.20 and 679.60 is: 1,016.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.20 : 1,210.20 = 679.60 : x
  2. Step 2: Convert to fraction form
    809.20/1,210.20 = 679.60/x
  3. Step 3: Cross multiply
    809.20x = 1,210.20 × 679.60
  4. Step 4: Simplify right side
    809.20x = 822,451.92
  5. Step 5: Solve for x
    x = 822,451.92/809.20
  6. Step 6: Final answer
    x = 1,016.38

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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.