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Finding the Fourth Proportional to 809.28, 1,213.80 and 289.26

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Solution

The fourth proportional to 809.28, 1,213.80 and 289.26 is: 433.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.28 : 1,213.80 = 289.26 : x
  2. Step 2: Convert to fraction form
    809.28/1,213.80 = 289.26/x
  3. Step 3: Cross multiply
    809.28x = 1,213.80 × 289.26
  4. Step 4: Simplify right side
    809.28x = 351,103.79
  5. Step 5: Solve for x
    x = 351,103.79/809.28
  6. Step 6: Final answer
    x = 433.85

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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.