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Finding the Fourth Proportional to 39.87, 54.63 and 39.69

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Solution

The fourth proportional to 39.87, 54.63 and 39.69 is: 54.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    39.87 : 54.63 = 39.69 : x
  2. Step 2: Convert to fraction form
    39.87/54.63 = 39.69/x
  3. Step 3: Cross multiply
    39.87x = 54.63 × 39.69
  4. Step 4: Simplify right side
    39.87x = 2,168.26
  5. Step 5: Solve for x
    x = 2,168.26/39.87
  6. Step 6: Final answer
    x = 54.38

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.