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Finding the Fourth Proportional to 385.65, 578.47 and 142.17

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Solution

The fourth proportional to 385.65, 578.47 and 142.17 is: 213.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.65 : 578.47 = 142.17 : x
  2. Step 2: Convert to fraction form
    385.65/578.47 = 142.17/x
  3. Step 3: Cross multiply
    385.65x = 578.47 × 142.17
  4. Step 4: Simplify right side
    385.65x = 82,241.08
  5. Step 5: Solve for x
    x = 82,241.08/385.65
  6. Step 6: Final answer
    x = 213.25

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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.