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Finding the Fourth Proportional to 39.69, 54.78 and 36.05

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Solution

The fourth proportional to 39.69, 54.78 and 36.05 is: 49.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    39.69 : 54.78 = 36.05 : x
  2. Step 2: Convert to fraction form
    39.69/54.78 = 36.05/x
  3. Step 3: Cross multiply
    39.69x = 54.78 × 36.05
  4. Step 4: Simplify right side
    39.69x = 1,974.41
  5. Step 5: Solve for x
    x = 1,974.41/39.69
  6. Step 6: Final answer
    x = 49.75

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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.