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Finding the Fourth Proportional to 816.05, 1,221.39 and 445.29

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Solution

The fourth proportional to 816.05, 1,221.39 and 445.29 is: 666.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    816.05 : 1,221.39 = 445.29 : x
  2. Step 2: Convert to fraction form
    816.05/1,221.39 = 445.29/x
  3. Step 3: Cross multiply
    816.05x = 1,221.39 × 445.29
  4. Step 4: Simplify right side
    816.05x = 543,872.75
  5. Step 5: Solve for x
    x = 543,872.75/816.05
  6. Step 6: Final answer
    x = 666.47

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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.