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Finding the Fourth Proportional to 206.88, 310.20 and 85.10

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Solution

The fourth proportional to 206.88, 310.20 and 85.10 is: 127.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.88 : 310.20 = 85.10 : x
  2. Step 2: Convert to fraction form
    206.88/310.20 = 85.10/x
  3. Step 3: Cross multiply
    206.88x = 310.20 × 85.10
  4. Step 4: Simplify right side
    206.88x = 26,398.02
  5. Step 5: Solve for x
    x = 26,398.02/206.88
  6. Step 6: Final answer
    x = 127.60

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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.