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Finding the Fourth Proportional to 808.79, 1,212.57 and 398.12

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Solution

The fourth proportional to 808.79, 1,212.57 and 398.12 is: 596.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    808.79 : 1,212.57 = 398.12 : x
  2. Step 2: Convert to fraction form
    808.79/1,212.57 = 398.12/x
  3. Step 3: Cross multiply
    808.79x = 1,212.57 × 398.12
  4. Step 4: Simplify right side
    808.79x = 482,742.31
  5. Step 5: Solve for x
    x = 482,742.31/808.79
  6. Step 6: Final answer
    x = 596.87

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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.