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Finding the Fourth Proportional to 38.70, 54.90 and 38.70

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Solution

The fourth proportional to 38.70, 54.90 and 38.70 is: 54.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    38.70 : 54.90 = 38.70 : x
  2. Step 2: Convert to fraction form
    38.70/54.90 = 38.70/x
  3. Step 3: Cross multiply
    38.70x = 54.90 × 38.70
  4. Step 4: Simplify right side
    38.70x = 2,124.63
  5. Step 5: Solve for x
    x = 2,124.63/38.70
  6. Step 6: Final answer
    x = 54.90

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Why These Related Problems?

These problems maintain the same ratio (1.42) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.