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Finding the Fourth Proportional to 816.05, 1,224.21 and 405.20

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Solution

The fourth proportional to 816.05, 1,224.21 and 405.20 is: 607.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    816.05 : 1,224.21 = 405.20 : x
  2. Step 2: Convert to fraction form
    816.05/1,224.21 = 405.20/x
  3. Step 3: Cross multiply
    816.05x = 1,224.21 × 405.20
  4. Step 4: Simplify right side
    816.05x = 496,054.47
  5. Step 5: Solve for x
    x = 496,054.47/816.05
  6. Step 6: Final answer
    x = 607.87

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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.