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Finding the Fourth Proportional to 721.40, 1,082.57 and 288.59

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Solution

The fourth proportional to 721.40, 1,082.57 and 288.59 is: 433.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.40 : 1,082.57 = 288.59 : x
  2. Step 2: Convert to fraction form
    721.40/1,082.57 = 288.59/x
  3. Step 3: Cross multiply
    721.40x = 1,082.57 × 288.59
  4. Step 4: Simplify right side
    721.40x = 312,412.02
  5. Step 5: Solve for x
    x = 312,412.02/721.40
  6. Step 6: Final answer
    x = 433.07

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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.