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Finding the Fourth Proportional to 809.96, 1,216.20 and 779

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Solution

The fourth proportional to 809.96, 1,216.20 and 779 is: 1,169.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.96 : 1,216.20 = 779 : x
  2. Step 2: Convert to fraction form
    809.96/1,216.20 = 779/x
  3. Step 3: Cross multiply
    809.96x = 1,216.20 × 779
  4. Step 4: Simplify right side
    809.96x = 947,419.80
  5. Step 5: Solve for x
    x = 947,419.80/809.96
  6. Step 6: Final answer
    x = 1,169.71

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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.