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Finding the Fourth Proportional to 806.12, 1,209.18 and 319.17

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Solution

The fourth proportional to 806.12, 1,209.18 and 319.17 is: 478.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    806.12 : 1,209.18 = 319.17 : x
  2. Step 2: Convert to fraction form
    806.12/1,209.18 = 319.17/x
  3. Step 3: Cross multiply
    806.12x = 1,209.18 × 319.17
  4. Step 4: Simplify right side
    806.12x = 385,933.98
  5. Step 5: Solve for x
    x = 385,933.98/806.12
  6. Step 6: Final answer
    x = 478.76

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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.