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Finding the Fourth Proportional to 721.79, 1,082.40 and 259.43

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Solution

The fourth proportional to 721.79, 1,082.40 and 259.43 is: 389.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.79 : 1,082.40 = 259.43 : x
  2. Step 2: Convert to fraction form
    721.79/1,082.40 = 259.43/x
  3. Step 3: Cross multiply
    721.79x = 1,082.40 × 259.43
  4. Step 4: Simplify right side
    721.79x = 280,800.65
  5. Step 5: Solve for x
    x = 280,800.65/721.79
  6. Step 6: Final answer
    x = 389.03

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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.