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Finding the Fourth Proportional to 808.17, 1,212.75 and 321.15

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Solution

The fourth proportional to 808.17, 1,212.75 and 321.15 is: 481.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    808.17 : 1,212.75 = 321.15 : x
  2. Step 2: Convert to fraction form
    808.17/1,212.75 = 321.15/x
  3. Step 3: Cross multiply
    808.17x = 1,212.75 × 321.15
  4. Step 4: Simplify right side
    808.17x = 389,474.66
  5. Step 5: Solve for x
    x = 389,474.66/808.17
  6. Step 6: Final answer
    x = 481.92

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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.