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Finding the Fourth Proportional to 728.97, 1,005.98 and 397.40

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Solution

The fourth proportional to 728.97, 1,005.98 and 397.40 is: 548.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.97 : 1,005.98 = 397.40 : x
  2. Step 2: Convert to fraction form
    728.97/1,005.98 = 397.40/x
  3. Step 3: Cross multiply
    728.97x = 1,005.98 × 397.40
  4. Step 4: Simplify right side
    728.97x = 399,774.67
  5. Step 5: Solve for x
    x = 399,774.67/728.97
  6. Step 6: Final answer
    x = 548.41

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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.