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Finding the Fourth Proportional to 83.79, 115.65 and 51.09

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Solution

The fourth proportional to 83.79, 115.65 and 51.09 is: 70.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    83.79 : 115.65 = 51.09 : x
  2. Step 2: Convert to fraction form
    83.79/115.65 = 51.09/x
  3. Step 3: Cross multiply
    83.79x = 115.65 × 51.09
  4. Step 4: Simplify right side
    83.79x = 5,908.56
  5. Step 5: Solve for x
    x = 5,908.56/83.79
  6. Step 6: Final answer
    x = 70.52

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.