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Finding the Fourth Proportional to 806.56, 1,208.22 and 421

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Solution

The fourth proportional to 806.56, 1,208.22 and 421 is: 630.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    806.56 : 1,208.22 = 421 : x
  2. Step 2: Convert to fraction form
    806.56/1,208.22 = 421/x
  3. Step 3: Cross multiply
    806.56x = 1,208.22 × 421
  4. Step 4: Simplify right side
    806.56x = 508,660.62
  5. Step 5: Solve for x
    x = 508,660.62/806.56
  6. Step 6: Final answer
    x = 630.65

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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.