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Finding the Fourth Proportional to 809.08, 1,212.91 and 479.21

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Solution

The fourth proportional to 809.08, 1,212.91 and 479.21 is: 718.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.08 : 1,212.91 = 479.21 : x
  2. Step 2: Convert to fraction form
    809.08/1,212.91 = 479.21/x
  3. Step 3: Cross multiply
    809.08x = 1,212.91 × 479.21
  4. Step 4: Simplify right side
    809.08x = 581,239.33
  5. Step 5: Solve for x
    x = 581,239.33/809.08
  6. Step 6: Final answer
    x = 718.39

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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.