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Finding the Fourth Proportional to 18.81, 25.88 and 15.30

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Solution

The fourth proportional to 18.81, 25.88 and 15.30 is: 21.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    18.81 : 25.88 = 15.30 : x
  2. Step 2: Convert to fraction form
    18.81/25.88 = 15.30/x
  3. Step 3: Cross multiply
    18.81x = 25.88 × 15.30
  4. Step 4: Simplify right side
    18.81x = 395.89
  5. Step 5: Solve for x
    x = 395.89/18.81
  6. Step 6: Final answer
    x = 21.05

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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.