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Finding the Fourth Proportional to 806.34, 1,209.33 and 319.20

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Solution

The fourth proportional to 806.34, 1,209.33 and 319.20 is: 478.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    806.34 : 1,209.33 = 319.20 : x
  2. Step 2: Convert to fraction form
    806.34/1,209.33 = 319.20/x
  3. Step 3: Cross multiply
    806.34x = 1,209.33 × 319.20
  4. Step 4: Simplify right side
    806.34x = 386,018.14
  5. Step 5: Solve for x
    x = 386,018.14/806.34
  6. Step 6: Final answer
    x = 478.73

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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.