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Finding the Fourth Proportional to 458.20, 687.21 and 214.66

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Solution

The fourth proportional to 458.20, 687.21 and 214.66 is: 321.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    458.20 : 687.21 = 214.66 : x
  2. Step 2: Convert to fraction form
    458.20/687.21 = 214.66/x
  3. Step 3: Cross multiply
    458.20x = 687.21 × 214.66
  4. Step 4: Simplify right side
    458.20x = 147,516.50
  5. Step 5: Solve for x
    x = 147,516.50/458.20
  6. Step 6: Final answer
    x = 321.95

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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.