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Finding the Fourth Proportional to 728.31, 1,092.45 and 289.80

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Solution

The fourth proportional to 728.31, 1,092.45 and 289.80 is: 434.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.31 : 1,092.45 = 289.80 : x
  2. Step 2: Convert to fraction form
    728.31/1,092.45 = 289.80/x
  3. Step 3: Cross multiply
    728.31x = 1,092.45 × 289.80
  4. Step 4: Simplify right side
    728.31x = 316,593.10
  5. Step 5: Solve for x
    x = 316,593.10/728.31
  6. Step 6: Final answer
    x = 434.69

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.