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Finding the Fourth Proportional to 782.70, 1,078.88 and 616.65

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Solution

The fourth proportional to 782.70, 1,078.88 and 616.65 is: 849.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    782.70 : 1,078.88 = 616.65 : x
  2. Step 2: Convert to fraction form
    782.70/1,078.88 = 616.65/x
  3. Step 3: Cross multiply
    782.70x = 1,078.88 × 616.65
  4. Step 4: Simplify right side
    782.70x = 665,288.27
  5. Step 5: Solve for x
    x = 665,288.27/782.70
  6. Step 6: Final answer
    x = 849.99

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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.