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Finding the Fourth Proportional to 728.66, 1,005.89 and 489.82

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Solution

The fourth proportional to 728.66, 1,005.89 and 489.82 is: 676.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.66 : 1,005.89 = 489.82 : x
  2. Step 2: Convert to fraction form
    728.66/1,005.89 = 489.82/x
  3. Step 3: Cross multiply
    728.66x = 1,005.89 × 489.82
  4. Step 4: Simplify right side
    728.66x = 492,705.04
  5. Step 5: Solve for x
    x = 492,705.04/728.66
  6. Step 6: Final answer
    x = 676.18

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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.