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Finding the Fourth Proportional to 385.32, 578.28 and 212.16

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Solution

The fourth proportional to 385.32, 578.28 and 212.16 is: 318.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.32 : 578.28 = 212.16 : x
  2. Step 2: Convert to fraction form
    385.32/578.28 = 212.16/x
  3. Step 3: Cross multiply
    385.32x = 578.28 × 212.16
  4. Step 4: Simplify right side
    385.32x = 122,687.88
  5. Step 5: Solve for x
    x = 122,687.88/385.32
  6. Step 6: Final answer
    x = 318.41

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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.