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Finding the Fourth Proportional to 806.69, 1,208.96 and 319.47

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Solution

The fourth proportional to 806.69, 1,208.96 and 319.47 is: 478.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    806.69 : 1,208.96 = 319.47 : x
  2. Step 2: Convert to fraction form
    806.69/1,208.96 = 319.47/x
  3. Step 3: Cross multiply
    806.69x = 1,208.96 × 319.47
  4. Step 4: Simplify right side
    806.69x = 386,227.85
  5. Step 5: Solve for x
    x = 386,227.85/806.69
  6. Step 6: Final answer
    x = 478.78

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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.