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Finding the Fourth Proportional to 311.94, 430.20 and 218.57

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Solution

The fourth proportional to 311.94, 430.20 and 218.57 is: 301.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.94 : 430.20 = 218.57 : x
  2. Step 2: Convert to fraction form
    311.94/430.20 = 218.57/x
  3. Step 3: Cross multiply
    311.94x = 430.20 × 218.57
  4. Step 4: Simplify right side
    311.94x = 94,026.66
  5. Step 5: Solve for x
    x = 94,026.66/311.94
  6. Step 6: Final answer
    x = 301.43

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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.