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Finding the Fourth Proportional to 207.25, 310.79 and 85.43

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Solution

The fourth proportional to 207.25, 310.79 and 85.43 is: 128.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    207.25 : 310.79 = 85.43 : x
  2. Step 2: Convert to fraction form
    207.25/310.79 = 85.43/x
  3. Step 3: Cross multiply
    207.25x = 310.79 × 85.43
  4. Step 4: Simplify right side
    207.25x = 26,550.97
  5. Step 5: Solve for x
    x = 26,550.97/207.25
  6. Step 6: Final answer
    x = 128.11

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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.