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Finding the Fourth Proportional to 39.88, 59.81 and 18.21

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Solution

The fourth proportional to 39.88, 59.81 and 18.21 is: 27.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    39.88 : 59.81 = 18.21 : x
  2. Step 2: Convert to fraction form
    39.88/59.81 = 18.21/x
  3. Step 3: Cross multiply
    39.88x = 59.81 × 18.21
  4. Step 4: Simplify right side
    39.88x = 1,089.14
  5. Step 5: Solve for x
    x = 1,089.14/39.88
  6. Step 6: Final answer
    x = 27.31

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.