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Finding the Fourth Proportional to 728.86, 1,005.87 and 449.11

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Solution

The fourth proportional to 728.86, 1,005.87 and 449.11 is: 619.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.86 : 1,005.87 = 449.11 : x
  2. Step 2: Convert to fraction form
    728.86/1,005.87 = 449.11/x
  3. Step 3: Cross multiply
    728.86x = 1,005.87 × 449.11
  4. Step 4: Simplify right side
    728.86x = 451,746.28
  5. Step 5: Solve for x
    x = 451,746.28/728.86
  6. Step 6: Final answer
    x = 619.80

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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.