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Finding the Fourth Proportional to 83.80, 115.54 and 54.69

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Solution

The fourth proportional to 83.80, 115.54 and 54.69 is: 75.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    83.80 : 115.54 = 54.69 : x
  2. Step 2: Convert to fraction form
    83.80/115.54 = 54.69/x
  3. Step 3: Cross multiply
    83.80x = 115.54 × 54.69
  4. Step 4: Simplify right side
    83.80x = 6,318.88
  5. Step 5: Solve for x
    x = 6,318.88/83.80
  6. Step 6: Final answer
    x = 75.40

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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.