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Finding the Fourth Proportional to 721.59, 1,087.79 and 660.09

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Solution

The fourth proportional to 721.59, 1,087.79 and 660.09 is: 995.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.59 : 1,087.79 = 660.09 : x
  2. Step 2: Convert to fraction form
    721.59/1,087.79 = 660.09/x
  3. Step 3: Cross multiply
    721.59x = 1,087.79 × 660.09
  4. Step 4: Simplify right side
    721.59x = 718,036.00
  5. Step 5: Solve for x
    x = 718,036.00/721.59
  6. Step 6: Final answer
    x = 995.07

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.