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Finding the Fourth Proportional to 427.72, 642.32 and 408.24

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Solution

The fourth proportional to 427.72, 642.32 and 408.24 is: 613.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.72 : 642.32 = 408.24 : x
  2. Step 2: Convert to fraction form
    427.72/642.32 = 408.24/x
  3. Step 3: Cross multiply
    427.72x = 642.32 × 408.24
  4. Step 4: Simplify right side
    427.72x = 262,219.63
  5. Step 5: Solve for x
    x = 262,219.63/427.72
  6. Step 6: Final answer
    x = 613.07

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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.