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Finding the Fourth Proportional to 809.19, 1,211.17 and 418.65

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Solution

The fourth proportional to 809.19, 1,211.17 and 418.65 is: 626.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.19 : 1,211.17 = 418.65 : x
  2. Step 2: Convert to fraction form
    809.19/1,211.17 = 418.65/x
  3. Step 3: Cross multiply
    809.19x = 1,211.17 × 418.65
  4. Step 4: Simplify right side
    809.19x = 507,052.48
  5. Step 5: Solve for x
    x = 507,052.48/809.19
  6. Step 6: Final answer
    x = 626.62

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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.