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Finding the Fourth Proportional to 728.40, 1,092.06 and 420.60

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Solution

The fourth proportional to 728.40, 1,092.06 and 420.60 is: 630.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.40 : 1,092.06 = 420.60 : x
  2. Step 2: Convert to fraction form
    728.40/1,092.06 = 420.60/x
  3. Step 3: Cross multiply
    728.40x = 1,092.06 × 420.60
  4. Step 4: Simplify right side
    728.40x = 459,320.44
  5. Step 5: Solve for x
    x = 459,320.44/728.40
  6. Step 6: Final answer
    x = 630.59

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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.