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Finding the Fourth Proportional to 789.31, 1,089.64 and 494.74

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Solution

The fourth proportional to 789.31, 1,089.64 and 494.74 is: 682.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    789.31 : 1,089.64 = 494.74 : x
  2. Step 2: Convert to fraction form
    789.31/1,089.64 = 494.74/x
  3. Step 3: Cross multiply
    789.31x = 1,089.64 × 494.74
  4. Step 4: Simplify right side
    789.31x = 539,088.49
  5. Step 5: Solve for x
    x = 539,088.49/789.31
  6. Step 6: Final answer
    x = 682.99

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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.