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Finding the Fourth Proportional to 385.30, 531.70 and 219.50

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Solution

The fourth proportional to 385.30, 531.70 and 219.50 is: 302.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.30 : 531.70 = 219.50 : x
  2. Step 2: Convert to fraction form
    385.30/531.70 = 219.50/x
  3. Step 3: Cross multiply
    385.30x = 531.70 × 219.50
  4. Step 4: Simplify right side
    385.30x = 116,704.39
  5. Step 5: Solve for x
    x = 116,704.39/385.30
  6. Step 6: Final answer
    x = 302.90

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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.