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Finding the Fourth Proportional to 720.81, 1,082.13 and 613.29

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Solution

The fourth proportional to 720.81, 1,082.13 and 613.29 is: 920.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.81 : 1,082.13 = 613.29 : x
  2. Step 2: Convert to fraction form
    720.81/1,082.13 = 613.29/x
  3. Step 3: Cross multiply
    720.81x = 1,082.13 × 613.29
  4. Step 4: Simplify right side
    720.81x = 663,659.51
  5. Step 5: Solve for x
    x = 663,659.51/720.81
  6. Step 6: Final answer
    x = 920.71

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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.