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Finding the Fourth Proportional to 809.17, 1,207.49 and 721.80

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Solution

The fourth proportional to 809.17, 1,207.49 and 721.80 is: 1,077.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.17 : 1,207.49 = 721.80 : x
  2. Step 2: Convert to fraction form
    809.17/1,207.49 = 721.80/x
  3. Step 3: Cross multiply
    809.17x = 1,207.49 × 721.80
  4. Step 4: Simplify right side
    809.17x = 871,568.09
  5. Step 5: Solve for x
    x = 871,568.09/809.17
  6. Step 6: Final answer
    x = 1,077.12

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.