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Finding the Fourth Proportional to 789.28, 1,089.21 and 494.72

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Solution

The fourth proportional to 789.28, 1,089.21 and 494.72 is: 682.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    789.28 : 1,089.21 = 494.72 : x
  2. Step 2: Convert to fraction form
    789.28/1,089.21 = 494.72/x
  3. Step 3: Cross multiply
    789.28x = 1,089.21 × 494.72
  4. Step 4: Simplify right side
    789.28x = 538,851.25
  5. Step 5: Solve for x
    x = 538,851.25/789.28
  6. Step 6: Final answer
    x = 682.71

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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.