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Finding the Fourth Proportional to 806.82, 1,209.75 and 319.61

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Solution

The fourth proportional to 806.82, 1,209.75 and 319.61 is: 479.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    806.82 : 1,209.75 = 319.61 : x
  2. Step 2: Convert to fraction form
    806.82/1,209.75 = 319.61/x
  3. Step 3: Cross multiply
    806.82x = 1,209.75 × 319.61
  4. Step 4: Simplify right side
    806.82x = 386,642.15
  5. Step 5: Solve for x
    x = 386,642.15/806.82
  6. Step 6: Final answer
    x = 479.22

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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.