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Finding the Fourth Proportional to 728.74, 1,005.68 and 397.19

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Solution

The fourth proportional to 728.74, 1,005.68 and 397.19 is: 548.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.74 : 1,005.68 = 397.19 : x
  2. Step 2: Convert to fraction form
    728.74/1,005.68 = 397.19/x
  3. Step 3: Cross multiply
    728.74x = 1,005.68 × 397.19
  4. Step 4: Simplify right side
    728.74x = 399,449.55
  5. Step 5: Solve for x
    x = 399,449.55/728.74
  6. Step 6: Final answer
    x = 548.14

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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.