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Finding the Fourth Proportional to 342.78, 513.49 and 219.21

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Solution

The fourth proportional to 342.78, 513.49 and 219.21 is: 328.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    342.78 : 513.49 = 219.21 : x
  2. Step 2: Convert to fraction form
    342.78/513.49 = 219.21/x
  3. Step 3: Cross multiply
    342.78x = 513.49 × 219.21
  4. Step 4: Simplify right side
    342.78x = 112,560.08
  5. Step 5: Solve for x
    x = 112,560.08/342.78
  6. Step 6: Final answer
    x = 328.37

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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.