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Finding the Fourth Proportional to 385.90, 578.12 and 212.29

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Solution

The fourth proportional to 385.90, 578.12 and 212.29 is: 318.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.90 : 578.12 = 212.29 : x
  2. Step 2: Convert to fraction form
    385.90/578.12 = 212.29/x
  3. Step 3: Cross multiply
    385.90x = 578.12 × 212.29
  4. Step 4: Simplify right side
    385.90x = 122,726.59
  5. Step 5: Solve for x
    x = 122,726.59/385.90
  6. Step 6: Final answer
    x = 318.03

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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.