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Finding the Fourth Proportional to 808.72, 1,212.12 and 479.20

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Solution

The fourth proportional to 808.72, 1,212.12 and 479.20 is: 718.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    808.72 : 1,212.12 = 479.20 : x
  2. Step 2: Convert to fraction form
    808.72/1,212.12 = 479.20/x
  3. Step 3: Cross multiply
    808.72x = 1,212.12 × 479.20
  4. Step 4: Simplify right side
    808.72x = 580,847.90
  5. Step 5: Solve for x
    x = 580,847.90/808.72
  6. Step 6: Final answer
    x = 718.23

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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.