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Finding the Fourth Proportional to 385.67, 578.49 and 142.09

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Solution

The fourth proportional to 385.67, 578.49 and 142.09 is: 213.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.67 : 578.49 = 142.09 : x
  2. Step 2: Convert to fraction form
    385.67/578.49 = 142.09/x
  3. Step 3: Cross multiply
    385.67x = 578.49 × 142.09
  4. Step 4: Simplify right side
    385.67x = 82,197.64
  5. Step 5: Solve for x
    x = 82,197.64/385.67
  6. Step 6: Final answer
    x = 213.13

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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.