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Finding the Fourth Proportional to 807.66, 1,211.75 and 320.85

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Solution

The fourth proportional to 807.66, 1,211.75 and 320.85 is: 481.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    807.66 : 1,211.75 = 320.85 : x
  2. Step 2: Convert to fraction form
    807.66/1,211.75 = 320.85/x
  3. Step 3: Cross multiply
    807.66x = 1,211.75 × 320.85
  4. Step 4: Simplify right side
    807.66x = 388,784.73
  5. Step 5: Solve for x
    x = 388,784.73/807.66
  6. Step 6: Final answer
    x = 481.37

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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.