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Finding the Fourth Proportional to 196.78, 295.12 and 128.30

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Solution

The fourth proportional to 196.78, 295.12 and 128.30 is: 192.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    196.78 : 295.12 = 128.30 : x
  2. Step 2: Convert to fraction form
    196.78/295.12 = 128.30/x
  3. Step 3: Cross multiply
    196.78x = 295.12 × 128.30
  4. Step 4: Simplify right side
    196.78x = 37,863.90
  5. Step 5: Solve for x
    x = 37,863.90/196.78
  6. Step 6: Final answer
    x = 192.42

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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.