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Finding the Fourth Proportional to 782.61, 1,081.31 and 618.09

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Solution

The fourth proportional to 782.61, 1,081.31 and 618.09 is: 854.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    782.61 : 1,081.31 = 618.09 : x
  2. Step 2: Convert to fraction form
    782.61/1,081.31 = 618.09/x
  3. Step 3: Cross multiply
    782.61x = 1,081.31 × 618.09
  4. Step 4: Simplify right side
    782.61x = 668,346.90
  5. Step 5: Solve for x
    x = 668,346.90/782.61
  6. Step 6: Final answer
    x = 854.00

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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.