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Finding the Fourth Proportional to 83.70, 115.31 and 79.16

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Solution

The fourth proportional to 83.70, 115.31 and 79.16 is: 109.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    83.70 : 115.31 = 79.16 : x
  2. Step 2: Convert to fraction form
    83.70/115.31 = 79.16/x
  3. Step 3: Cross multiply
    83.70x = 115.31 × 79.16
  4. Step 4: Simplify right side
    83.70x = 9,127.56
  5. Step 5: Solve for x
    x = 9,127.56/83.70
  6. Step 6: Final answer
    x = 109.05

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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.