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Finding the Fourth Proportional to 28.10, 38.80 and 18.42

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Solution

The fourth proportional to 28.10, 38.80 and 18.42 is: 25.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.10 : 38.80 = 18.42 : x
  2. Step 2: Convert to fraction form
    28.10/38.80 = 18.42/x
  3. Step 3: Cross multiply
    28.10x = 38.80 × 18.42
  4. Step 4: Simplify right side
    28.10x = 714.70
  5. Step 5: Solve for x
    x = 714.70/28.10
  6. Step 6: Final answer
    x = 25.43

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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.