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Finding the Fourth Proportional to 424.20, 636.24 and 218.64

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Solution

The fourth proportional to 424.20, 636.24 and 218.64 is: 327.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    424.20 : 636.24 = 218.64 : x
  2. Step 2: Convert to fraction form
    424.20/636.24 = 218.64/x
  3. Step 3: Cross multiply
    424.20x = 636.24 × 218.64
  4. Step 4: Simplify right side
    424.20x = 139,107.51
  5. Step 5: Solve for x
    x = 139,107.51/424.20
  6. Step 6: Final answer
    x = 327.93

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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.