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Finding the Fourth Proportional to 427.22, 640.84 and 399.88

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Solution

The fourth proportional to 427.22, 640.84 and 399.88 is: 599.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.22 : 640.84 = 399.88 : x
  2. Step 2: Convert to fraction form
    427.22/640.84 = 399.88/x
  3. Step 3: Cross multiply
    427.22x = 640.84 × 399.88
  4. Step 4: Simplify right side
    427.22x = 256,259.10
  5. Step 5: Solve for x
    x = 256,259.10/427.22
  6. Step 6: Final answer
    x = 599.83

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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.