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Finding the Fourth Proportional to 385.45, 578.37 and 212.25

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Solution

The fourth proportional to 385.45, 578.37 and 212.25 is: 318.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.45 : 578.37 = 212.25 : x
  2. Step 2: Convert to fraction form
    385.45/578.37 = 212.25/x
  3. Step 3: Cross multiply
    385.45x = 578.37 × 212.25
  4. Step 4: Simplify right side
    385.45x = 122,757.97
  5. Step 5: Solve for x
    x = 122,757.97/385.45
  6. Step 6: Final answer
    x = 318.48

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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.