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Finding the Fourth Proportional to 206.71, 310.12 and 76.78

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Solution

The fourth proportional to 206.71, 310.12 and 76.78 is: 115.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.71 : 310.12 = 76.78 : x
  2. Step 2: Convert to fraction form
    206.71/310.12 = 76.78/x
  3. Step 3: Cross multiply
    206.71x = 310.12 × 76.78
  4. Step 4: Simplify right side
    206.71x = 23,810.05
  5. Step 5: Solve for x
    x = 23,810.05/206.71
  6. Step 6: Final answer
    x = 115.19

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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.