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Finding the Fourth Proportional to 728.49, 1,005 and 492.35

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Solution

The fourth proportional to 728.49, 1,005 and 492.35 is: 679.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.49 : 1,005 = 492.35 : x
  2. Step 2: Convert to fraction form
    728.49/1,005 = 492.35/x
  3. Step 3: Cross multiply
    728.49x = 1,005 × 492.35
  4. Step 4: Simplify right side
    728.49x = 494,816.15
  5. Step 5: Solve for x
    x = 494,816.15/728.49
  6. Step 6: Final answer
    x = 679.23

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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.