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Finding the Fourth Proportional to 385.20, 531.58 and 219.40

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Solution

The fourth proportional to 385.20, 531.58 and 219.40 is: 302.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.20 : 531.58 = 219.40 : x
  2. Step 2: Convert to fraction form
    385.20/531.58 = 219.40/x
  3. Step 3: Cross multiply
    385.20x = 531.58 × 219.40
  4. Step 4: Simplify right side
    385.20x = 116,628.65
  5. Step 5: Solve for x
    x = 116,628.65/385.20
  6. Step 6: Final answer
    x = 302.77

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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.