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Finding the Fourth Proportional to 806.16, 1,209.31 and 319.09

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Solution

The fourth proportional to 806.16, 1,209.31 and 319.09 is: 478.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    806.16 : 1,209.31 = 319.09 : x
  2. Step 2: Convert to fraction form
    806.16/1,209.31 = 319.09/x
  3. Step 3: Cross multiply
    806.16x = 1,209.31 × 319.09
  4. Step 4: Simplify right side
    806.16x = 385,878.73
  5. Step 5: Solve for x
    x = 385,878.73/806.16
  6. Step 6: Final answer
    x = 478.66

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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.