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Finding the Fourth Proportional to 385.49, 531.90 and 219.71

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Solution

The fourth proportional to 385.49, 531.90 and 219.71 is: 303.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.49 : 531.90 = 219.71 : x
  2. Step 2: Convert to fraction form
    385.49/531.90 = 219.71/x
  3. Step 3: Cross multiply
    385.49x = 531.90 × 219.71
  4. Step 4: Simplify right side
    385.49x = 116,861.09
  5. Step 5: Solve for x
    x = 116,861.09/385.49
  6. Step 6: Final answer
    x = 303.15

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.