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Finding the Fourth Proportional to 386.14, 578.50 and 212.55

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Solution

The fourth proportional to 386.14, 578.50 and 212.55 is: 318.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.14 : 578.50 = 212.55 : x
  2. Step 2: Convert to fraction form
    386.14/578.50 = 212.55/x
  3. Step 3: Cross multiply
    386.14x = 578.50 × 212.55
  4. Step 4: Simplify right side
    386.14x = 122,960.18
  5. Step 5: Solve for x
    x = 122,960.18/386.14
  6. Step 6: Final answer
    x = 318.43

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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.