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Finding the Fourth Proportional to 458.18, 686.87 and 214.64

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Solution

The fourth proportional to 458.18, 686.87 and 214.64 is: 321.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    458.18 : 686.87 = 214.64 : x
  2. Step 2: Convert to fraction form
    458.18/686.87 = 214.64/x
  3. Step 3: Cross multiply
    458.18x = 686.87 × 214.64
  4. Step 4: Simplify right side
    458.18x = 147,432.51
  5. Step 5: Solve for x
    x = 147,432.51/458.18
  6. Step 6: Final answer
    x = 321.78

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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.