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Finding the Fourth Proportional to 385.40, 531.78 and 219.59

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Solution

The fourth proportional to 385.40, 531.78 and 219.59 is: 302.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.40 : 531.78 = 219.59 : x
  2. Step 2: Convert to fraction form
    385.40/531.78 = 219.59/x
  3. Step 3: Cross multiply
    385.40x = 531.78 × 219.59
  4. Step 4: Simplify right side
    385.40x = 116,770.91
  5. Step 5: Solve for x
    x = 116,770.91/385.40
  6. Step 6: Final answer
    x = 302.99

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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.