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Finding the Fourth Proportional to 721.80, 1,082.58 and 412.65

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Solution

The fourth proportional to 721.80, 1,082.58 and 412.65 is: 618.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.80 : 1,082.58 = 412.65 : x
  2. Step 2: Convert to fraction form
    721.80/1,082.58 = 412.65/x
  3. Step 3: Cross multiply
    721.80x = 1,082.58 × 412.65
  4. Step 4: Simplify right side
    721.80x = 446,726.64
  5. Step 5: Solve for x
    x = 446,726.64/721.80
  6. Step 6: Final answer
    x = 618.91

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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.