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Finding the Fourth Proportional to 808.82, 1,213.38 and 398.45

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Solution

The fourth proportional to 808.82, 1,213.38 and 398.45 is: 597.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    808.82 : 1,213.38 = 398.45 : x
  2. Step 2: Convert to fraction form
    808.82/1,213.38 = 398.45/x
  3. Step 3: Cross multiply
    808.82x = 1,213.38 × 398.45
  4. Step 4: Simplify right side
    808.82x = 483,474.29
  5. Step 5: Solve for x
    x = 483,474.29/808.82
  6. Step 6: Final answer
    x = 597.75

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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.