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Finding the Fourth Proportional to 423.90, 635.70 and 218.40

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Solution

The fourth proportional to 423.90, 635.70 and 218.40 is: 327.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    423.90 : 635.70 = 218.40 : x
  2. Step 2: Convert to fraction form
    423.90/635.70 = 218.40/x
  3. Step 3: Cross multiply
    423.90x = 635.70 × 218.40
  4. Step 4: Simplify right side
    423.90x = 138,836.88
  5. Step 5: Solve for x
    x = 138,836.88/423.90
  6. Step 6: Final answer
    x = 327.52

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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.