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Finding the Fourth Proportional to 83.79, 126.05 and 79.70

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Solution

The fourth proportional to 83.79, 126.05 and 79.70 is: 119.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    83.79 : 126.05 = 79.70 : x
  2. Step 2: Convert to fraction form
    83.79/126.05 = 79.70/x
  3. Step 3: Cross multiply
    83.79x = 126.05 × 79.70
  4. Step 4: Simplify right side
    83.79x = 10,045.16
  5. Step 5: Solve for x
    x = 10,045.16/83.79
  6. Step 6: Final answer
    x = 119.88

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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.