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Finding the Fourth Proportional to 206.91, 310.05 and 85.08

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Solution

The fourth proportional to 206.91, 310.05 and 85.08 is: 127.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.91 : 310.05 = 85.08 : x
  2. Step 2: Convert to fraction form
    206.91/310.05 = 85.08/x
  3. Step 3: Cross multiply
    206.91x = 310.05 × 85.08
  4. Step 4: Simplify right side
    206.91x = 26,379.05
  5. Step 5: Solve for x
    x = 26,379.05/206.91
  6. Step 6: Final answer
    x = 127.49

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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.