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Finding the Fourth Proportional to 207.78, 285.20 and 198.87

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Solution

The fourth proportional to 207.78, 285.20 and 198.87 is: 272.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    207.78 : 285.20 = 198.87 : x
  2. Step 2: Convert to fraction form
    207.78/285.20 = 198.87/x
  3. Step 3: Cross multiply
    207.78x = 285.20 × 198.87
  4. Step 4: Simplify right side
    207.78x = 56,719.13
  5. Step 5: Solve for x
    x = 56,719.13/207.78
  6. Step 6: Final answer
    x = 272.97

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.