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Finding the Fourth Proportional to 811.31, 1,118.49 and 612.05

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Solution

The fourth proportional to 811.31, 1,118.49 and 612.05 is: 843.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.31 : 1,118.49 = 612.05 : x
  2. Step 2: Convert to fraction form
    811.31/1,118.49 = 612.05/x
  3. Step 3: Cross multiply
    811.31x = 1,118.49 × 612.05
  4. Step 4: Simplify right side
    811.31x = 684,571.80
  5. Step 5: Solve for x
    x = 684,571.80/811.31
  6. Step 6: Final answer
    x = 843.79

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.