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Finding the Fourth Proportional to 83.58, 115.33 and 77.78

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Solution

The fourth proportional to 83.58, 115.33 and 77.78 is: 107.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    83.58 : 115.33 = 77.78 : x
  2. Step 2: Convert to fraction form
    83.58/115.33 = 77.78/x
  3. Step 3: Cross multiply
    83.58x = 115.33 × 77.78
  4. Step 4: Simplify right side
    83.58x = 8,969.79
  5. Step 5: Solve for x
    x = 8,969.79/83.58
  6. Step 6: Final answer
    x = 107.32

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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.