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Finding the Fourth Proportional to 378.18, 521.92 and 218.72

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Solution

The fourth proportional to 378.18, 521.92 and 218.72 is: 301.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.18 : 521.92 = 218.72 : x
  2. Step 2: Convert to fraction form
    378.18/521.92 = 218.72/x
  3. Step 3: Cross multiply
    378.18x = 521.92 × 218.72
  4. Step 4: Simplify right side
    378.18x = 114,154.34
  5. Step 5: Solve for x
    x = 114,154.34/378.18
  6. Step 6: Final answer
    x = 301.85

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.