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Finding the Fourth Proportional to 721.65, 1,081.49 and 330.68

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Solution

The fourth proportional to 721.65, 1,081.49 and 330.68 is: 495.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.65 : 1,081.49 = 330.68 : x
  2. Step 2: Convert to fraction form
    721.65/1,081.49 = 330.68/x
  3. Step 3: Cross multiply
    721.65x = 1,081.49 × 330.68
  4. Step 4: Simplify right side
    721.65x = 357,628.16
  5. Step 5: Solve for x
    x = 357,628.16/721.65
  6. Step 6: Final answer
    x = 495.57

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.