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Finding the Fourth Proportional to 329.70, 455.10 and 198.78

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Solution

The fourth proportional to 329.70, 455.10 and 198.78 is: 274.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    329.70 : 455.10 = 198.78 : x
  2. Step 2: Convert to fraction form
    329.70/455.10 = 198.78/x
  3. Step 3: Cross multiply
    329.70x = 455.10 × 198.78
  4. Step 4: Simplify right side
    329.70x = 90,464.78
  5. Step 5: Solve for x
    x = 90,464.78/329.70
  6. Step 6: Final answer
    x = 274.39

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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.