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Finding the Fourth Proportional to 786.86, 1,084.97 and 644.63

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Solution

The fourth proportional to 786.86, 1,084.97 and 644.63 is: 888.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    786.86 : 1,084.97 = 644.63 : x
  2. Step 2: Convert to fraction form
    786.86/1,084.97 = 644.63/x
  3. Step 3: Cross multiply
    786.86x = 1,084.97 × 644.63
  4. Step 4: Simplify right side
    786.86x = 699,400.40
  5. Step 5: Solve for x
    x = 699,400.40/786.86
  6. Step 6: Final answer
    x = 888.85

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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.