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Finding the Fourth Proportional to 778.89, 1,072.65 and 717.33

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Solution

The fourth proportional to 778.89, 1,072.65 and 717.33 is: 987.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    778.89 : 1,072.65 = 717.33 : x
  2. Step 2: Convert to fraction form
    778.89/1,072.65 = 717.33/x
  3. Step 3: Cross multiply
    778.89x = 1,072.65 × 717.33
  4. Step 4: Simplify right side
    778.89x = 769,444.02
  5. Step 5: Solve for x
    x = 769,444.02/778.89
  6. Step 6: Final answer
    x = 987.87

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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.