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Finding the Fourth Proportional to 809, 1,213.53 and 261.14

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Solution

The fourth proportional to 809, 1,213.53 and 261.14 is: 391.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    809 : 1,213.53 = 261.14 : x
  2. Step 2: Convert to fraction form
    809/1,213.53 = 261.14/x
  3. Step 3: Cross multiply
    809x = 1,213.53 × 261.14
  4. Step 4: Simplify right side
    809x = 316,901.22
  5. Step 5: Solve for x
    x = 316,901.22/809
  6. Step 6: Final answer
    x = 391.72

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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.