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Finding the Fourth Proportional to 18.40, 25.39 and 13.80

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Solution

The fourth proportional to 18.40, 25.39 and 13.80 is: 19.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    18.40 : 25.39 = 13.80 : x
  2. Step 2: Convert to fraction form
    18.40/25.39 = 13.80/x
  3. Step 3: Cross multiply
    18.40x = 25.39 × 13.80
  4. Step 4: Simplify right side
    18.40x = 350.38
  5. Step 5: Solve for x
    x = 350.38/18.40
  6. Step 6: Final answer
    x = 19.04

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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.