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Finding the Fourth Proportional to 806.11, 1,209.76 and 312.59

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Solution

The fourth proportional to 806.11, 1,209.76 and 312.59 is: 469.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    806.11 : 1,209.76 = 312.59 : x
  2. Step 2: Convert to fraction form
    806.11/1,209.76 = 312.59/x
  3. Step 3: Cross multiply
    806.11x = 1,209.76 × 312.59
  4. Step 4: Simplify right side
    806.11x = 378,163.38
  5. Step 5: Solve for x
    x = 378,163.38/806.11
  6. Step 6: Final answer
    x = 469.12

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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.