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Finding the Fourth Proportional to 728.10, 1,092.35 and 419.90

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Solution

The fourth proportional to 728.10, 1,092.35 and 419.90 is: 629.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.10 : 1,092.35 = 419.90 : x
  2. Step 2: Convert to fraction form
    728.10/1,092.35 = 419.90/x
  3. Step 3: Cross multiply
    728.10x = 1,092.35 × 419.90
  4. Step 4: Simplify right side
    728.10x = 458,673.35
  5. Step 5: Solve for x
    x = 458,673.35/728.10
  6. Step 6: Final answer
    x = 629.96

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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.