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Finding the Fourth Proportional to 781.88, 1,078.50 and 634.22

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Solution

The fourth proportional to 781.88, 1,078.50 and 634.22 is: 874.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.88 : 1,078.50 = 634.22 : x
  2. Step 2: Convert to fraction form
    781.88/1,078.50 = 634.22/x
  3. Step 3: Cross multiply
    781.88x = 1,078.50 × 634.22
  4. Step 4: Simplify right side
    781.88x = 684,006.27
  5. Step 5: Solve for x
    x = 684,006.27/781.88
  6. Step 6: Final answer
    x = 874.82

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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.