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Finding the Fourth Proportional to 728.28, 1,086.48 and 649.92

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Solution

The fourth proportional to 728.28, 1,086.48 and 649.92 is: 969.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.28 : 1,086.48 = 649.92 : x
  2. Step 2: Convert to fraction form
    728.28/1,086.48 = 649.92/x
  3. Step 3: Cross multiply
    728.28x = 1,086.48 × 649.92
  4. Step 4: Simplify right side
    728.28x = 706,125.08
  5. Step 5: Solve for x
    x = 706,125.08/728.28
  6. Step 6: Final answer
    x = 969.58

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.