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Finding the Fourth Proportional to 206.51, 309.79 and 76.49

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Solution

The fourth proportional to 206.51, 309.79 and 76.49 is: 114.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.51 : 309.79 = 76.49 : x
  2. Step 2: Convert to fraction form
    206.51/309.79 = 76.49/x
  3. Step 3: Cross multiply
    206.51x = 309.79 × 76.49
  4. Step 4: Simplify right side
    206.51x = 23,695.55
  5. Step 5: Solve for x
    x = 23,695.55/206.51
  6. Step 6: Final answer
    x = 114.75

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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.